NARRATOR: NAZI FORTIFICATIONS ON AN EPIC SCALE...

IT'S MORE LIKE A MEDIEVAL CASTLE WITH ALL THESE STAIRCASES.

NARRATOR: A GROUP OF TINY ISLANDS THE GERMANS SEIZE AND STRENGTHEN AT AN ASTONISHING RATE...

THE CHANNEL ISLANDS WERE THE MOST HEAVILY FORTIFIED PLACE ON EARTH, FORT KNOX TIMES 10.

NARRATOR: HITLER BECOMES OBSESSED...

I WILL NOT GIVE UP THESE ISLANDS TO THE BRITISH.

NARRATOR: COVERING THEM IN A NETWORK OF BUNKERS, STRONGPOINTS, AND GUN EMPLACEMENTS... AND THEN READY TO FIRE.

BANG!

NARRATOR: PACKED WITH 37,000 GERMAN TROOPS PRIMED AND READY FOR AN ALLIED COUNTERATTACK.

THIS IS THE STORY OF THE MOST POWERFUL NAZI ISLAND FORTRESS OF THE SECOND WORLD WAR, BUILT ON BRITISH SOIL-- HITLER'S ISLAND MEGAFORTRESS.

THE BIGGEST CONSTRUCTION PROJECTS OF WORLD WAR II, ORDERED BY HITLER TO SECURE WORLD DOMINATION... [SPEAKING GERMAN] NARRATOR: NOW THEY SURVIVE AS DARK REMINDERS OF THE FUHRER'S FANATICAL MILITARY AMBITIONS.

THESE ARE THE SECRETS OF THE NAZI MEGA WEAPONS.

NARRATOR: JUNE 6, 1944.

LUFTWAFFE COMMAND HQ ON THE CHANNEL ISLANDS.

IT MUST BE A MISTAKE.

WHAT IS IT?

HUNDREDS OF ENEMY PLANES AND SHIPS.

RAISE THE ALARM!

[ALARM BLARING] NARRATOR: LESS THAN A MILE AWAY, 20-YEAR-OLD ANTI-AIRCRAFT GUNNER HUBERT WOLF IS JUST STARTING HIS DAY.

MAN AS WOLF: I TOOK MY FIELD GLASSES TO LOOK UP AT THE SKIES, AS I DID EVERY MORNING.

I WAS SHOCKED TO SEE HUNDREDS OF AMERICAN BOMBERS ON A DIRECT APPROACH FROM THE NORTH.

ALARM!

THE ALLIES ARE HERE!

ROLL BACK TO FIGHTING POSITIONS!

THE ALLIES ARE HERE!

MAN AS WOLF: I WAS TERRIFIED.

IF THEY DROPPED THEIR BOMBS ON OUR ISLAND, WE WOULD ALL BE FINISHED.

NARRATOR: THE REMAINS OF THE NAZI WAR MACHINE STILL LITTER THE CHANNEL ISLANDS TODAY.

IN THE HEART OF A QUAINT, LITTLE TOWN ON THE ISLAND OF ALDERNEY, MILITARY HISTORIAN DR. PETER LIEB HAS COME TO DISCOVER ONE OF THEM.

WOW!

STUNNING!

NARRATOR: THIS TOWER WAS THE NERVE CENTER OF LUFTWAFFE COMMAND.

THIS IS THE MAIN ENTRANCE TO THE SITE.

HERE, ANYONE ATTACKING WOULD BE SHOT RIGHT HERE, FROM THIS MACHINE GUN POST.

ANOTHER MACHINE GUN POST.

SO, ANYONE TRYING TO GET INTO THIS PLACE WITH A WRONG INTENT WOULD BE SHOT FROM THE LEFT OR FROM THE CENTER.

NARRATOR: BY 1944, THIS MEGASTRUCTURE BRISTLED WITH ADVANCED TELECOMMUNICATIONS EQUIPMENT, AS THE NAZIS SCOURED THE AIRWAVES FOR EVIDENCE OF AN ALLIED ATTACK.

TODAY, IT OPERATES AS A STORAGE FACILITY FOR A CELL PHONE COMPANY.

AH, LIGHT DOESN'T WORK.

THIS IS THE COMMAND POST, WHERE ALL THE MESSAGES CAME IN.

AN ENIGMA MACHINE PROBABLY SITTING SOMEWHERE IN ONE OF THESE ROOMS.

ALL OF THE INFORMATION COMING IN FROM THE VARIOUS RADAR STATIONS, AND ALSO FROM THE OBSERVERS, FROM AERIAL RECONNAISSANCE, AND ALL THE INFORMATION PASSED ON THROUGH THE CHAIN OF COMMAND TO THE HIGH COMMAND OF THE LUFTWAFFE.

A HATCH FOR PASSING INFORMATION, MESSAGES, OR TELEGRAMS FROM ONE ROOM TO THE OTHER.

HERE WE GET OUR FIRST VIEWS OUT ON THE SEA.

YOU ALREADY GET A SENSE HOW IMPORTANT ALDERNEY WAS.

60 MILES THIS DIRECTION IS ENGLAND.

SO, THE GERMAN SOLDIERS SITTING IN THIS TOWER KNEW IF THE ENEMY IS COMING, HE MUST COME FROM THIS DIRECTION.

WOW!

HAH!

BREATHTAKING!

NARRATOR: THE STORY OF THE NAZIS' HOLD ON THE CHANNEL ISLANDS BEGINS IN JUNE 1940.

GERMANY LAUNCHES A LIGHTNING STRIKE ON FRANCE, AND, SUDDENLY, THE CHANNEL ISLANDS, THE BIGGEST OF WHICH ARE JERSEY, GUERNSEY, AND ALDERNEY, ARE WITHIN EASY REACH.

THE BRITISH GOVERNMENT BELIEVES THESE ISLANDS ARE IMPOSSIBLE TO DEFEND, AND ORDERS A COMPLETE MILITARY EVACUATION.

HEINKEL BOMBERS CONDUCT THE FIRST NAZI RAIDS, UNAWARE THE ISLANDS ARE NOW SITTING DUCKS.

THE ISLANDERS HAVE NO IDEA WHAT'S ABOUT TO HIT THEM.

THERE'S NO AIR RAID SIRENS, THERE'S NO EARLY WARNING SYSTEM ON THE CHANNEL ISLANDS.

SUDDENLY WITH THESE BOMBS FALLING IS A KIND OF STARK, TERRIBLE REALIZATION THAT THEY ARE SUDDENLY ON THE FRONT LINE.

AND THAT IS DEEPLY SHOCKING.

NARRATOR: ON JUNE 30, THE NAZIS LAND AT GUERNSEY AIRPORT.

THE OCCUPATION BEGINS.

HITLER IS DETERMINED NOT TO LOSE HIS FOOTHOLD ON BRITISH SOIL.

[SPEAKING GERMAN] COUNTERMEASURES IN THE CHANNEL ISLANDS MUST ENSURE THAT ANY BRITISH ATTACK FAILS BEFORE A LANDING IS EFFECTED.

I ORDERED A PERMANENT FORTIFICATION OF THE ISLANDS.

TURN THEM INTO AN IMPREGNABLE FORTRESS.

THEY MUST BE SECURED AT MAXIMUM SPEED.

YES, MEIN FUHRER.

WE WILL COMMENCE IMMEDIATELY.

MAN: HITLER WANTS TO TURN THE CHANNEL ISLANDS INTO A FORTRESS.

THERE'S GONNA BE CONCRETE GALORE, THERE'S GONNA BE TUNNELS, THERE'S GONNA BE BUNKERS, THERE'S GONNA BE NAVAL GUNS, THERE'S GONNA BE AIRFIELDS, THERE'S GONNA BE CAMPS.

YOU KNOW, THIS PLACE IS JUST GONNA BE SORT OF BRISTLING WITH DEFENSIVE EQUIPMENT.

NARRATOR: HITLER APPOINTS COUNT RUDOLF VON SCHMETTOW AS COMMANDER OF THE ISLANDS.

VON SCHMETTOW KNOWS THEY DON'T HAVE THE INFRASTRUCTURE TO COPE WITH A MASSIVE BUILDING PROGRAM.

GENTLEMEN, WE FACE GREAT DIFFICULTIES AND DELAYS IN THE FORTRESS CONSTRUCTION HERE FOR A NUMBER OF REASONS.

THE INADEQUATE RAILROADS, THE RELOADING FACILITIES IN THE HARBOR ARE COMPLETELY INSUFFICIENT.

IT'S A COMPLETE NIGHTMARE.

NARRATOR: WORK ON HITLER'S MEGAFORTRESS BEGINS WITH A VAST PROGRAM OF ROAD AND RAIL CONSTRUCTION.

20,000 TONS OF STEEL AND CONCRETE ARE SHIPPED INTO THE ISLANDS EVERY MONTH.

EVEN AFTER HIS ATTENTION TURNS TO RUSSIA IN 1941, HITLER STILL KEEPS A CLOSE EYE ON HIS CHANNEL ISLAND FORTRESS.

HOLLAND: WITH HITLER TURNING EAST, WHAT HE REALLY NEEDS TO BE DOING IS FOCUSING EVERYTHING ON GOING EAST, PUTTING ALL HIS RESOURCES THERE.

WHAT HE DOESN'T NEED IS A TINY OUTCROP OF LITTLE ISLANDS JUST OFF THE FRENCH COAST, AND THEN STUFFING IT FULL OF TUNNELS AND CONCRETE AND BUNKERS AND ALL THE REST OF IT.

NARRATOR: THE OCCUPATION OF THE ISLANDS IS A MASSIVE PROPAGANDA COUP.

HITLER'S DETERMINED NOT TO LET THEM GO.

YOU MUST PRESS AHEAD WITH THE FORTIFICATION.

I FEAR THE BRITISH WILL ATTACK AT ANY MOMENT.

HOLLAND: STRATEGICALLY, OVERALL, IT JUST MAKES NO SENSE.

NARRATOR: HITLER'S GOAL IS AN INTEGRATED ISLAND FORTRESS, THE LIKE OF WHICH THE WORLD HAS NEVER SEEN.

A SERIES OF INTERCONNECTED GUN POSITIONS, OBSERVATION TOWERS, STRONGPOINTS, AND TUNNELS, TO WITHSTAND ATTACK FROM SEA OR AIR.

BUT HITLER ISN'T ONLY INTERESTED IN FORTIFYING THE ISLANDS.

HE DECIDES THEY HAVE A ROLE IN THE 1,000 YEAR REICH, ONCE THE WAR IS WON.

HITLER: THE CHANNEL ISLANDS, BECAUSE OF THEIR WONDERFUL CLIMATE, CONSTITUTE A MARVELOUS LOCATION FOR THE STRENGTH THROUGH JOY ORGANIZATION.

AFTER THE WAR, THE ISLANDS MUST REMAIN GERMAN.

OUR SOLDIERS CAN RECOVER THERE.

WE MUST HOLD ON TO THEM.

[MAN SPEAKING GERMAN] NARRATOR: ULTIMATELY, THE MEGAFORTRESS WILL BECOME A NAZI ISLAND PARADISE.

THE SECOND PHASE OF BUILDING HITLER'S ISLAND MEGAFORTRESS BEGINS.

OH, I CAN ALREADY SEE CONCRETE.

HERE IT IS.

WOW!

THAT LOOKS LIKE A CRATER.

IT'S AMAZING!

IT'S HUGE.

ENORMOUS!

NARRATOR: AT THE BATTERIE MIRUS ON GUERNSEY, OVER 100,000 TONS OF CONCRETE IS USED TO BUILD 4 ENORMOUS NAVAL GUN POSITIONS.

LIEB: THE SHEER SIZE OF IT, JUST FOR ONE SINGLE GUN.

THE BARREL, 45 FEET WEIGHING THE ENTIRE GUN, 51 TONS AND THE MOUNTING PLATFORM, A SPECIALLY DESIGNED MOUNTING PLATFORM, ALSO WEIGHING 40 TONS.

THE GUN COULD SWIVEL ABOUT TWO DEGREES PER SECOND.

SO, THIS MEANS IT TOOK 3 MINUTES FOR THE WHOLE GUN TO SWIVEL AROUND.

OVERALL, THE GUN COULD FIRE UP TO 30 MILES.

NARRATOR: TWO OF THE 4 GUN EMPLACEMENTS AT BATTERIE MIRUS ARE DISGUISED TO LOOK LIKE QUAINT ENGLISH COTTAGES.

BUT HIDDEN BENEATH THEM LIE AMMUNITION STORES, GENERATORS, HEATING AND VENTILATION SYSTEMS, AND PERSONNEL ACCOMMODATION FOR 72 MEN.

ONLY THE GUNS, RANGE FINDERS, AND CREW ENTRANCE SIT ABOVE THE SURFACE.

LIEB: THIS IS VERY LIKELY THE ENTRANCE FOR THE CREW.

IN GERMAN, "FEIND HORT MIT," "THE ENEMY LISTENS," SO WATCH OUT.

BE CAREFUL WHAT YOU SAY.

A SWASTIKA.

THE EMBLEM FOR THE GERMAN ARMED FORCES.

NORMALLY THEY WORE AN EAGLE WITH A SWASTIKA LIKE THAT ON THEIR BREAST OF THEIR UNIFORM.

OH!

ANOTHER DRAWING.

"WIE FAHREN GEGEN ENGELAND."

"WE ARE GOING AGAINST ENGLAND."

JUST SHOWS WHO THE ENEMY WAS HERE IN THIS PLACE.

WHAT IS THIS?

ARE THESE DRAINS?

NO, IT'S STEEL!

MUST BE TRACKS.

NOW I SEE WHAT IT IS LIKE.

HERE, THE GERMAN LORRIES BROUGHT THE SHELLS, HOISTED THEM ONTO TROLLEYS THAT WERE HERE ON THESE TRACKS.

THE TROLLEY IS BEING PUSHED BY A NUMBER OF GERMAN SOLDIERS BACK INTO THE BUNKER.

WOW!

AMAZING!

IT FEELS LIKE BACK IN THE WAR.

AH!

NOW I FULLY GET IT.

THIS HERE IS THE AMMUNITION ROOM.

OH, HERE ARE THE TRACKS FOR THE SHELLS, ON THE ROOF.

WHEN THERE WAS THE ALARM TO FIRE, THE AMMUNITION WAS HOISTED FROM HERE, WHERE THE MEN LOADED THE SHELL ONTO THE TROLLEY THAT WAS WAITING OUTSIDE.

THE TROLLEY IS PUSHED BACK AGAIN ALONG THE TRACKS.

THE CORDITE GOES ONTO THE TROLLEY.

PUSHED ALONG THESE TRACKS HERE AGAIN THE TROLLEY, WITH ALL THEIR SHELLS READY TO FIRE.

THE SHELLS ARE LOADED ONTO A SECOND TROLLEY.

THE TROLLEY GOES TOWARDS THE GUN, AND THEN READY TO FIRE.

BANG!

NARRATOR: AS HIS ONLY GRIP ON BRITAIN, HITLER'S ATTENTION TO THE DETAILS OF THE ISLANDS' DEFENSES VERGES ON THE FANATICAL.

HAVE YOU GOT THE PLAN READY?

[SPEAKING GERMAN] SHOW ME.

SOMETHING'S MISSING.

LOOK AT THIS.

THIS IS UNFORGIVABLE.

I TOLD YOU THIS IS OF THE HIGHEST IMPORTANCE.

THERE'S A BUNKER MISSING.

DO IT AGAIN.

I'M SORRY.

OF COURSE.

NARRATOR: SUCH IS HITLER'S OBSESSION, ONE ISLAND, ALDERNEY, IS GIVEN THE CODENAME "ADOLF."

IT HAS BEEN CLEARED OF CIVILIANS, AND IS BEING TRANSFORMED INTO A MASSIVE MILITARY BASE.

ONE OF OVER 3,000 MEN SENT TO THE ISLAND TO MAN THESE FORTIFICATIONS IS ANTI-AIRCRAFT GUNNER HUBERT WOLF.

HE GETS AN ORDER TO EMBARK IMMEDIATELY FOR A NIGHT CROSSING FROM FRANCE.

MAN AS WOLF: WE BOARDED A SMALL VESSEL OF THE GERMAN NAVY IN CHERBOURG.

WE WERE PUT ON THE FLOORS OF THE VARIOUS DECKS, AND STARTED OUR NIGHT JOURNEY TO ALDERNEY.

IT WAS A VERY STORMY NIGHT, AND MOST OF US, NEVER HAVING BEEN ON A SHIP BEFORE, WERE PROMPTLY SEASICK.

[RETCHING] NARRATOR: WITH HIS ISLAND FORTRESS UNDER WAY, HITLER'S PERSONAL QUEST TO ETHNICALLY CLEANSE ALL OF EUROPE NOW REACHES BRITISH SOIL.

MOST JEWS HAD EVACUATED BEFORE THE NAZIS ARRIVED, BUT THOSE WHO STAYED HAD ALREADY BEEN BARRED FROM OWNING BUSINESSES AND WORKING AS OFFICIALS.

ON SEPTEMBER 15, 1942, HITLER ORDERS THE DEPORTATION OF ALL NON-NATIVE CHANNEL ISLANDERS, INCLUDING ALL REMAINING JEWS.

AS ISLANDS' COMMANDER, VON SCHMETTOW TREADS A FINE LINE BETWEEN IMPLEMENTING HITLER'S DEMANDS... OH, MORNING!

OH.

THANK YOU.

NARRATOR: AND MAINTAINING THE RESPECT OF THE ISLANDERS.

WORK CONTINUES ON FORTIFYING THE ISLANDS.

PHASE 3 IS A NETWORK OF NAVAL OBSERVATION TOWERS.

CONFLICT ARCHAEOLOGIST DR. TONY POLLARD HAS BEEN GRANTED ACCESS TO ONE OF THEM.

NOW, THAT IS MEGA.

THIS IS WHAT I CAME TO SEE, THIS AMAZING BIG STRUCTURE.

IT'S KNOWN AS A MARINE PIELSTAND, AND IT'S FOR MARINE RANGE-FINDING.

NARRATOR: THIS MASSIVE CONCRETE BUILDING'S SOLE PURPOSE IS TO SPOT, IDENTIFY, AND PRECISELY LOCATE ENEMY TARGETS.

AND EVEN FROM HERE, IT LOOKS LIKE THE WALLS ARE ABOUT 2 1/2 METERS THICK.

PHENOMENAL STRUCTURE.

BUT THIS IS THE KILLER, ITS LOCATION ON THIS CLIFF FACE.

THERE'S ALMOST A BEAUTY TO THIS, AND THE LOCALS DESCRIBE IT AS THE "ODEON."

THEY CALL IT THE "ODEON" BECAUSE IT LOOKS A BIT LIKE AN ART DECO CINEMA FROM THE 1930s.

BUT IT'S ICONIC.

YOU ONLY FIND THEM IN THE CHANNEL ISLANDS.

IT'S A NAZI MEGASTRUCTURE TO BEAT THEM ALL.

[THUMPING] OH!

I DIDN'T EXPECT IT TO BE SPOOKY.

OH, GOOD GRIEF!

THERE'S STEPS EVERYWHERE.

GOOD GRIEF, IT'S HUGE!

IT'S MORE LIKE A MEDIEVAL CASTLE WITH ALL THESE STAIRCASES.

NARRATOR: THE DIRECTION AND RANGE-FINDING TOWER HAS 3 LEVELS; EACH MONITORS THE HORIZON FOR DIFFERENT GUN BATTERIES STATIONED INLAND.

ONCE SPOTTED, THE PRECISE DISTANCE AND DIRECTION TO AN ENEMY SHIP IS COMMUNICATED BACK TO THE GUNS.

WITH A NETWORK OF 9 TOWERS AROUND THE COASTLINE, THE NAZIS CAN DEFEND THEMSELVES FROM A NAVAL ATTACK FROM ANY DIRECTION.

OH, WOW!

THAT IS BEAUTIFUL.

THIS IS LIKE ONE OF THOSE PANORAMIC PHOTOGRAPHS.

A COMPLETE 180.

YOU CAN SEE OVER TO THE EAST, IT MUST BE, BECAUSE THERE'S JERSEY JUST POKING OUT OF THE HAZE.

STRAIGHT AHEAD, WE'VE GOT FRANCE, WHICH MUST BE ROUGHLY NORTH, 'CAUSE WE'VE GOT THE EDGE OF THE BAY JUTTING OUT.

AND THE GERMANS WERE PETRIFIED THAT THE ALLIES WERE GONNA INVADE, WERE GONNA ATTACK, OR EVEN BRING THEIR SHIPS IN CLOSE ENOUGH TO BOMBARD FROM THE SEA.

NOW, THIS IS INTERESTING.

THE GERMANS WOULD USE RADIOS, OBVIOUSLY, BUT THEY ALSO HAD A VERY GOOD CUSTOM-BUILT TELEPHONE SYSTEM.

AND THAT'S WHAT THIS IS.

YOU CAN SEE THE CABLES LEADING OUT.

THEY HAD MILES AND MILES OF BURIED TELEPHONE CABLE ON THE ISLANDS.

AND THIS IS FAIRLY WELL RUSTED BUT LOOK THERE, LOOK, YOU CAN STILL SEE A MAKER'S MARK.

TOP FLOOR.

THERE ARE OTHER FEATURES IN HERE.

I CAN SEE ALREADY THAT THERE ARE TUBES RUNNING ALL THE WAY ALONG HERE.

THAT ONE JUST GOES STRAIGHT OUT.

WHAT THEY MIGHT BE, AND WE COME BACK TO THIS IDEA OF IT BEING LIKE A MEDIEVAL CASTLE, IS A TUBE THROUGH WHICH YOU COULD DROP A HAND GRENADE, AND IT WOULD GO DOWN THE TUBE, SHOOT OUT FROM THE WALL, AND DROP ON THEIR HEADS.

THERE ARE STILL MYSTERIES.

WE DON'T KNOW EVERYTHING.

AND IN A WAY, THESE ARE LIKE, YOU KNOW, THESE ARE LIKE ANCIENT MONUMENTS.

IN SOME CASES, THE SECRETS DIED WITH THE PEOPLE THAT MANNED THEM.

NARRATOR: THE ENORMOUS NAZI GUN EMPLACEMENTS AND RANGE-FINDERS ON THE CHANNEL ISLANDS MEAN ANY BRITISH SHIP THAT STRAYS WITHIN 30 MILES IS LIKELY TO BE BLOWN OUT OF THE WATER.

BUT HITLER HAS EVEN BIGGER PLANS.

THE NEXT PHASE OF CONSTRUCTING HIS MEGAFORTRESS IS ABOUT TO BEGIN.

THE CHANNEL ISLANDS, 1942.

HITLER HAS DEMANDED THE CONSTRUCTION OF A VAST NETWORK OF TUNNELS.

THEIR PURPOSE: TO PROVIDE PROTECTION FOR EQUIPMENT, AMMUNITION, AND PERSONNEL.

THE OTHER THING ONE HAS TO REALIZE ABOUT THE GERMANS ON THE CHANNEL ISLANDS, AND ANYWHERE, IS THAT THEY JUST DON'T DO ANYTHING BY HALVES.

SO, AGAIN, IT'S NOT JUST A QUESTION OF BUILDING NAVAL GUNS, AND THEN BUILDING RANGE-FINDING OBSERVATION TOWERS.

THEY THEN START BUILDING TUNNELS, YOU KNOW, 30 MILES OF TUNNELS UNDER THE CHANNEL ISLANDS.

IT'S JUST A PHENOMENAL ENGINEERING FEAT.

NARRATOR: IN TOTAL, 8.6 MILLION CUBIC FEET OF EARTH AND ROCK ARE DUG FROM THE ISLANDS.

THIS IS THE HO2 TUNNEL, AND I'M LED TO BELIEVE IT'S REALLY VERY SPECIAL, SO, I'M INCREDIBLY EXCITED ABOUT GETTING ACCESS TO IT.

GOOD GRIEF!

WOW!

NARRATOR: THIS IS ONE OF THE FEW TUNNELS ON THE ISLANDS THE BRITISH DID NOT CLEAR OF NAZI EQUIPMENT.

POLLARD: IT'S AMAZING TO SEE THAT SOME OF IT IS STILL LYING HERE IN THIS INCREDIBLE GRAVEYARD OF EQUIPMENT.

I MEAN, LOOK AT THAT.

LOOK AT THE BEARINGS ON THAT.

I THINK THAT MIGHT BE THE LIMBER FOR AN ARTILLERY PIECE.

YOU COULD DRIVE A TRAIN THROUGH THIS, NO PROBLEM AT ALL.

LOOK AT THIS.

LOOK AT THE SIZE OF THIS PIECE.

LOOK, IT'S GOT A ROTATING DISC ON THE BASE.

THIS IS A RADAR SYSTEM KNOWN AS THE WURZBURG, AND THESE WERE USED TO CONTROL ANTI-AIRCRAFT FIRE.

ALLOWED THE GUNS TO LOCK ON TO THE TARGET.

AND AGAIN, INDICATIVE OF THE LENGTHS TO WHICH HITLER WAS GOING TO MAKE THIS PLACE IMPREGNABLE.

LOOK, ON THE WALL HERE YOU CAN SEE THESE SCRATCH MARKS.

THEY'VE BEEN CREATED BY CATERPILLAR TRACKS CRASHING INTO THE WALL.

AND THE POINT IS THAT FOR A VEHICLE TO HIT THE SIDE, THERE MAY BE TWO OF THEM, SIDE-BY-SIDE.

THIS HAS BEEN STUFFED FULL.

I LOVE ALL THESE LITTLE FORENSIC TRACES THEY LEAVE BEHIND.

THEY'RE SOMETIMES MORE EXCITING THAN THE REALLY OBVIOUS STUFF.

NARRATOR: ABOVE GROUND, HUBERT WOLF AND HIS ANTI-AIRCRAFT UNIT ARE BECOMING INCREASINGLY BORED, REPEATING DRILLS FOR ANY ALLIED COUNTERATTACK.

[SIGH] ALL RIGHT, LET'S GO, BOYS!

TO YOUR POSITIONS.

OK, LOAD!

35 DEGREES TO THE WEST.

WHEN YOU ARE READY, FIRE AT WILL.

CEASE FIRE!

MAN AS WOLF: WE WERE RESTRICTED TO DAILY GUN PRACTICES.

WE WERE TOLD TO BE ON GUARD AROUND THE CLOCK, SO, WE WERE LOOKING UP AT THE SKY FOR BRITISH PLANES, BUT NOTHING HAPPENED.

VERY GOOD, LADS!

THAT'S IT FOR TODAY.

DISMISSED.

NARRATOR: WOLF'S ANTI-AIRCRAFT POSITION IS ONE OF 86 BATTERIES AND OVER 400 FLAK GUNS STATIONED ON THE ISLANDS.

ALONGSIDE GUN EMPLACEMENTS, TOWERS, AND TUNNELS, THE NAZIS BUILD A SERIES OF STRONGPOINTS THROUGHOUT THE ISLANDS.

ONE OF THE MOST HEAVILY FORTIFIED IS STRONGPOINT JOSEFSBERG, ON ALDERNEY.

FORTIFICATIONS EXPERT ARTHUR VAN BEVEREN HAS COME TO THE ISLAND TO INVESTIGATE.

THE GERMANS INVADED THE CHANNEL ISLANDS IN 1940, AND WHAT THEY FOUND WERE ALL THESE FORTS, ALL OVER THE ISLANDS.

SO, WHAT THEY DID, THEY REUSED THE OLD VICTORIAN FORTS.

PRETTY DANGEROUS.

VICTORIAN STAIRS ARE GONE.

PROBABLY USED TO BE WOODEN STAIRS UP HERE.

THIS IS THE ANTI-AIRCRAFT POSITION AND THERE'S A SMALL BUNKER UNDERNEATH.

WE CAN TAKE A LOOK INSIDE, SEE WHAT'S THERE.

WOW.

THIS IS PRETTY AMAZING.

IT ACTUALLY LOOKS LIKE THE STEEL PROTECTION PLATE FOR THE MACHINE GUNNER.

SO, HE'D BE IN BETWEEN THE SHIELDS WITH THE MACHINE GUN LIKE THIS, DUH DUH DUH.

AND YOU'D BE PRETTY PROTECTED AGAINST BULLETS AND SMALL SHRAPNEL, YEAH.

SO, LET'S SEE WHAT'S UP HERE.

IT LOOKS LIKE JUST A VICTORIAN HALLWAY.

IT GOES DOWN REAL DEEP, BUT THEN HERE ARE SOME OLD VICTORIAN ROOMS, BUT I CAN SEE THE LIGHT COMING FROM THE SEA AND IT'S JUST A PERFECT SPOT FOR THE BIGGEST SEARCHLIGHT IN THE STRONGPOINT.

IT WAS A 2-FEET SEARCHLIGHT ON A TRACK AND WHEN IT WAS USED, IT WAS DRIVEN OUT FROM HERE RIGHT TO THE EDGE OF THE FORTRESS, JUST OVER THIS HUGE STEEP WALL 45 FEET, AND IN FRONT WE SEE THE BEACH WHICH WAS MINED AND BARBED WIRED, SO, IMPOSSIBLE TO BREACH FOR ANY ALLIED LANDINGS.

NARRATOR: BUILT TO WITHSTAND ATTACK FROM ANY DIRECTION, THIS STRONGPOINT IS EQUIPPED WITH SEARCHLIGHT POSITIONS, 4-INCH-CALIBER MACHINE GUN CASEMENTS, AND ANTI-AIRCRAFT GUNS.

BUT IT'S THE NORTHERN TIP, KNOWN AS THE "BIG NOSE," THAT THE NAZIS TURN INTO THEIR MEGABUNKER.

THEY POUR CONCRETE INTO THE EXISTING FORT TO CREATE A BOMBPROOF ACCOMMODATION BLOCK, TOPPED WITH A STEEL OBSERVATION AND MACHINE GUN POSITION.

VAN BEVEREN: SO, THE WIND IS COMING IN AND IT'S WET AGAIN.

SALTWATER COMING IN EVERY DAY FOR 70 YEARS BATTERING THIS BUNKER.

AND THIS WAS THE GUN POSITION THAT HAD A 4-INCH GUN AND THIS ONE WAS COVERING THE BREAKWATER.

IT USED TO BE CLOSED OFF WITH A STEEL PLATE BECAUSE THE GUN WAS HERE.

SO, IF YOU WERE INVADING AND YOU WERE ON THE BREAKWATER, YOU WERE COMPLETELY BLOWN AWAY BY THIS GUN.

SO, THIS BUNKER IS ONE OF A KIND, AND IT HAS ABOUT 3 OR 3 1/2 LEVELS, AND WE'RE GOING DOWN ONE LEVEL NOW.

IT'S REALLY BIG STAIRS.

HA HA HA!

THIS IS 7 FEET OF REINFORCED CONCRETE, AND BEHIND IT IS THE ORIGINAL VICTORIAN WALL.

THE CREW OF THIS FORTRESS, AND I GUESS IT WAS ABOUT 50 MEN INSIDE THIS BUNKER, WERE ALL INSIDE HERE, AND THEY HAD BEDS HANGING HERE, AND THE BEDS WERE HANGING ON THESE HOOKS, AND YOU HAD 3 LAYERS OF BEDS.

ONE HERE, ONE HERE, AND ONE DOWN HERE, SO, IT WAS A PRETTY SMALL PLACE FOR ALL THESE GUYS.

NARRATOR: BY 1943, THERE HAS STILL BEEN NO ALLIED COUNTERATTACK.

HITLER REGARDS HIS FORTIFICATION OF THE ISLANDS A SUCCESS.

THE CONCEPT IS TAKEN FURTHER, TO 1,700 MILES OF COASTLINE DEFENDING NORTHERN EUROPE.

THE ATLANTIC WALL.

NOW WITH AN AREA 20 TIMES LONGER TO FORTIFY, SOME OF HITLER'S SENIOR GENERALS START TO QUESTION HIS UNWAVERING PREOCCUPATION WITH THE ISLANDS.

I WILL NOT GIVE UP THESE ISLANDS TO THE BRITISH.

IF THEY'RE GOING TO ATTACK US, I AM SURE THIS IS WHERE THEY WILL START.

WE MUST FINISH THE ISLAND FORTRESS.

THIS IS HIS ISLAND MADNESS.

HOLLAND: HITLER IS CONSTANTLY PUTTING AN ARM BEHIND THE BACK OF HIS WEHRMACHT, OF HIS ARMED FORCES, BY HIS MEDDLING, BY HIS STRATEGIC INTERFERENCE.

HIS STAFF MIGHT SAY, YOU KNOW, "MEIN FUHRER, I THINK YOU MIGHT WANT TO RECONSIDER THAT, BECAUSE I'M NOT SURE THAT'S A GOOD IDEA," BUT YOU'RE A BRAVE MAN IF YOU'RE GONNA STAND UP TO ADOLF HITLER AND SAY THAT.

NARRATOR: 37,000 GERMAN TROOPS ARE NOW STATIONED ON THE CHANNEL ISLANDS.

COMPARED TO FIGHTING ON THE EASTERN FRONT, LIFE IS QUIET FOR MEN LIKE HUBERT WOLF.

[UPBEAT MUSIC PLAYING] MAN AS WOLF: WE FELT LIKE PRISONERS ON ALDERNEY.

THE FOOD WAS BAD, AND THERE WERE NO WOMEN.

IT DIDN'T FEEL LIKE A LIFE AND WE HAD NOTHING TO DO.

[SLOW MUSIC PLAYING ON RADIO] BUT ONE MORNING WHILE LISTENING TO THE RADIO, WE HEARD THAT A FAMOUS GERMAN SWING BAND WERE VISITING ALDERNEY THAT EVENING.

I WAS SO HAPPY, I STARTED PRETENDING TO DANCE WITH THE LOVE I HAD LEFT BEHIND IN GERMANY.

[TRUMPET PLAYING] AND WHEN I SAW THEM THAT EVENING, IT WAS THE GREATEST TWO HOURS OF MY LIFE.

I COULD FORGET THE WAR AND LIVE.

[GUNFIRE] NARRATOR: WINTER, 1943.

HITLER'S ATTACK ON RUSSIA IS FALTERING.

MORE MEN ARE NEEDED ON THE FRONT, CAUSING PROBLEMS FOR THE CHANNEL ISLANDS' COMMANDER.

MAN AS VON SCHMETTOW: ABOUT 6,000 YOUNG, WELL-TRAINED NCOs AND MEN HAD TO BE EXCHANGED FOR MEN THAT WERE MUCH OLDER AND LITTLE TRAINED.

THE CONTINENTAL DIVISIONS DID NOT HAVE THE FIGHTING POWER NECESSARY FOR CARRYING OUT THE COUNTEROFFENSIVES.

HOLLAND: VON SCHMETTOW IS NOT A RADICALIZED NAZI OR ANYTHING LIKE THAT, YOU KNOW?

HE COMES FROM A TRADITIONAL MILITARY BACKGROUND, BUT, OF COURSE, YOU KNOW, HE'S CONSTANTLY HAVING TO RESPOND TO THE DICTATES FROM BERLIN, AND THESE BECOME EVER MORE DIFFICULT TO ENACT.

NARRATOR: BUT AS GERMAN SOLDIERS ARE SENT EAST, CAPTURED RUSSIANS AND EASTERN EUROPEANS ARE SHIPPED WEST, USED AS SLAVE LABOR ON THE ISLANDS AND HELD IN CAMPS.

FOR DECADES, NOBODY REALLY KNEW WHAT HAPPENED HERE.

I'M HEADING TO THE GATES OF LAGER SYLT, WHICH IS ONE OF 4 CAMPS ON ALDERNEY, BUT IT'S THE ONLY ONE THAT'S A CONCENTRATION CAMP RUN BY THE SS.

THERE WERE 1,000 INMATES HERE, AND THEY INCLUDED UKRAINIANS, RUSSIANS, POLES, FRENCH JEWS, AND POLITICAL PRISONERS.

THESE PEOPLE WERE REGARDED AS THE "UNTERMENSCHEN."

THEY'RE LESS THAN HUMAN.

WE'VE GOT A PLAN.

BUT IT'S GOING TO BE DIFFICULT, I THINK, TO MAKE OUT MUCH IN THIS UNDERGROWTH.

SO, THERE'S AN ACCOMMODATION HUT HERE, AND GIVEN THERE'S 1,000 MEN IN THE CAMP OR 1,000 PEOPLE, WE KNOW THERE WERE WOMEN AS WELL, OVER 100 PEOPLE IN ONE OF THESE HUTS, VERY UNCOMFORTABLE.

NARRATOR: THE ACCOMMODATION BLOCKS AT SYLT WERE FRENCH ARMY HUTS, MEASURING ONLY 100 FEET IN LENGTH.

THE ENTIRE CAMP IS JUST TWO ACRES IN SIZE.

WORKERS HAD A HARD TIME ON THE OTHER ISLANDS, BUT ON THOSE OTHER ISLANDS, THERE WAS A LOCAL POPULATION, AND IF THEY COULD THEY WOULD HELP OUT THE WORKERS, PROVIDE THEM WITH A BIT OF FOOD, SCRAPS OF CLOTHING.

BUT ALDERNEY WAS DIFFERENT.

THE LOCAL POPULATION HERE HAD BEEN EVACUATED BEFORE THE INVASION.

THERE WERE ONLY A HANDFUL OF LOCALS LEFT.

SO, BASICALLY, ALL YOU'VE GOT ARE THE PRISONERS AND THEIR GUARDS.

A VERY, VERY LONELY EXISTENCE.

AND WE'RE ON THE EDGE OF THE CAMP JUST HERE.

WIRE PROBABLY CAME THROUGH JUST WHERE WE ARE AND I'M GOING TO HEAD OUT THIS WAY BECAUSE THE CORNER SHOULD BE MARKED IN SOME WAY.

YEP, THIS IS WHAT I WAS LOOKING FOR.

THIS STRANGE CONCRETE STRUCTURE LOOKS A BIT LIKE A SPACESHIP, BUT I'VE SEEN THESE IN FRANCE.

AND IT IS, YEAH, IT'S A SENTRY BOX.

AND ONE OF THESE AT EACH CORNER OF THE CAMP PROVIDING PROTECTION AND SECURITY.

BUT IT NEVER CEASES TO AMAZE ME HOW HORRIBLE THESE ARE.

THE DOOR HAS COME OFF.

THERE IS A CONCRETE DOOR ABOUT 6 INCHES THICK AND THE GUY WOULD BE IN HERE... SUNK DOWN, SO, THESE EYE SLOT, WELL, THIS EYE SLOT, YOU CAN SEE THE ENEMY IF THE ENEMY WERE APPROACHING AND THERE'S A HIGHER ONE HERE.

NOT MUCH USE FOR ME, ACTUALLY.

SO, THIS WOULD NOT BE DESIGNED TO FUNCTION AS A PILLBOX, A BIGGER STRUCTURE.

THIS IS REALLY BLAST PROTECTION, SO, IF THERE IS AN ATTACK, EITHER FROM THE AIR OR FROM GROUND TROOPS USING ARTILLERY OR GRENADES, A SOLDIER COULD DUCK IN HERE AND TAKE COVER, BUT NONETHELESS EXTREMELY CLAUSTROPHOBIC AND PRETTY AWFUL.

NARRATOR: OTHER HAUNTING REMNANTS OF THE CONCENTRATION CAMP REMAIN.

OH, WE'VE GOT STONEWORK HERE.

AND A STAIRWAY.

LOOK AT THESE STAIRS.

THIS IS LIKE NOTHING ELSE WE'VE SEEN HERE.

THAT IS A SERIOUS BUNKER, WHATEVER IT IS.

SNAILS ON THE WALL.

WOW!

GOOD GRIEF!

WELL, THIS, I THINK, EXPLAINS THIS ROOM.

WE'VE GOT THIS BIG, IRON PLATFORM, WITH HEAVY DUTY WATER PIPES LEADING INTO IT.

IT'S GOT TO BE A BOILER.

THIS IS A BOILER ROOM.

AND, LOOK, YOU CAN SEE THE COAL DUST.

SO, THAT CHUTE HAS SUPPLIED THE COAL THAT'S BEEN PUT INTO THE BOILER, BURNED, HEATING THE WATER.

AND, HERE, YOU'VE GOT PIPES RUNNING UP TO THE SURFACE, PROVIDING HOT WATER.

THIS IS THE SHOWER AND BATH BLOCK.

IT'S CLEARLY NOT FOR THE USE OF THE WORKERS AND THE PRISONERS.

THIS MUST BE FOR THE USE OF THE OFFICERS OF THE CAMP.

AND WE DON'T HAVE TO LEAVE BY THE STAIRWAY, BECAUSE THE PLAN DOES SHOW A TUNNEL.

YOU CAN SEE WHERE THE TIMBER SHUTTERING'S BEEN HOLDING THE ROOF UP WHILE THE CONCRETE SETS.

BUT WE'RE BACK OUT IN DAYLIGHT.

AND I KNOW FROM THE PLAN THAT WE'RE NOW OUTSIDE THE FENCE.

WE'RE OUTSIDE THE CAMP.

BUT THIS IS NO ESCAPE TUNNEL, BECAUSE JUST HERE WAS THE COMMANDANT'S HOUSE.

A GUY CALLED MAXIMILIAN LIST.

AND EVEN THOUGH I CAN'T SEE ANYTHING OF THE BUILDING, BECAUSE OF THE OVERGROWTH, I'M GUESSING IT PROBABLY LOOKED PRETTY NICE.

SO, HE'S ISOLATED HIMSELF FROM IT.

THE ONLY VIEW HE'S GOT IS A BEAUTIFUL ONE OUT TO SEA.

IT'S KINDA HORRIBLE, REALLY, BUT IT'S QUITE TYPICAL OF CONCENTRATION CAMPS, WHERE THE COMMANDANTS LIVED OUTSIDE, MAYBE IN A PICTURESQUE, LITTLE COTTAGE, SOMETIMES WITH THEIR FAMILIES, GETTING AWAY FROM THE HORROR THAT WAS HAPPENING INSIDE THE WIRE.

NARRATOR: THE SLAVE WORKERS HAVE TO ENDURE DAILY BEATINGS, MALNUTRITION, AND DISEASE.

AN ESTIMATED 4,000 DIE ON THE CHANNEL ISLANDS.

MAN: I WOULD LIKE TO COMPLAIN MOST STRONGLY ABOUT THE ACTION OF THE GERMAN ARMY.

THE TREATMENT OF THE SLAVES AND THE PEOPLE OF JERSEY, JUST TOTALLY UNACCEPTABLE... NARRATOR: ONE OF THE ISLAND'S POLITICIANS, ALEXANDER COUTANCHE, APPEALS ON BEHALF OF THE SLAVE WORKERS.

WHAT YOU HAVE TO UNDERSTAND IS THAT I AM UNDER STRICT ORDERS FROM BERLIN, WHICH I PERSONALLY CANNOT OVERRULE.

NARRATOR: THESE ORDERS DEMAND YET MORE FORTIFICATIONS, AND THE BIGGEST MEGASTRUCTURE ON THE ISLAND IS STILL TO COME.

BY EARLY 1944, HITLER'S IMPREGNABLE FORTRESS NEARS COMPLETION.

HOLLAND: THE CHANNEL ISLANDS WERE THE MOST HEAVILY FORTIFIED PLACE ON EARTH.

IT IS JUST FORT KNOX TIMES 10, BECAUSE YOU'VE GOT 175,000 MINES, 65,000 FEET OF ANTI-TANK WALLS, 440 GUNS, 86 ANTI-AIRCRAFT BATTERIES.

I MEAN, THIS PLACE IS ABSOLUTELY BRISTLING WITH DEFENSIVE FIRE POWER, ANTI-INVASION OBSTACLES, AND SO ON.

NARRATOR: BUT THE CROWNING GLORY OF THE ISLAND FORTRESS IS ALMOST ENTIRELY INVISIBLE FROM THE AIR.

THIS UNASSUMING DOORWAY LEADS INTO THE BIGGEST MEGASTRUCTURE ON THE ISLANDS.

NARRATOR: THE GUERNSEY TUNNELS COMPLEX IS DESIGNED AS AN AMMUNITION STORE AND ACCOMMODATION BLOCK.

IT'S ONE OF THE LARGEST SINGLE ENGINEERING PROJECTS EVER UNDERTAKEN BY THE NAZIS.

POLLARD: IF EVER YOU WANNA GET AN IDEA OF HITLER'S AMBITIONS FOR THE CHANNEL ISLANDS, STEP INTO THIS TUNNEL.

A MILLION CUBIC FEET OF ROCK WAS HEWN AWAY TO CREATE 1 1/4 MILES OF TUNNELS.

THE WALLS ARE LINED WITH 15,000 TONS OF CONCRETE.

THE SCALE IS JUST PHENOMENAL.

YOU COULD BE IN HERE FOREVER.

LOOK--HERE WE'VE GOT AN ELECTRICAL JUNCTION BOX.

THERE'S AN ENTIRE INFRASTRUCTURE OF ELECTRICITY, AIR CONDITIONING.

OH.

THEY'RE SO OBVIOUS.

YOU CAN LOOK AT ALL THE CONCRETE STRUCTURES YOU WANT BUT IT'S DIFFICULT AT TIMES TO PUT A HUMAN FACE ON THINGS.

BUT THIS JUST DRIVES IT HOME.

YOU'VE GOT SOMEBODY WALKING DOWN HERE WHILE THIS CONCRETE IS STILL DAMP.

BUT IT DOES DRIVE IT HOME THAT THESE THINGS DIDN'T APPEAR OUT OF NOWHERE.

WE'VE GOT AT ONE POINT 16,000 LABORERS HEWING AWAY ON THE ISLANDS.

NARRATOR: LYING SOME 75 FEET BELOW GROUND, THE TUNNELS PROVIDE COMPLETE PROTECTION FROM NAVAL ARTILLERY FIRE AND AERIAL BOMBARDMENT.

SPANNING 75,000 SQUARE FEET, THEY ARE ENTIRELY SELF-SUFFICIENT, WITH THEIR OWN WATER SUPPLY, KITCHEN FACILITIES, EVEN THEIR OWN CINEMA.

LOOK AT THE CURVE ON THIS CORNER.

YOU CAN SEE THE GRAIN OF THE WOOD IMPRESSED IN THE CONCRETE FROM THE SHUTTERING.

AND IT'S BENT ROUND.

IT'S ALMOST SHIPBUILDING TECHNOLOGY HERE.

THEY'RE WARPING THE PLANKS TO TAKE THIS CURVE ROUND, AND BRINGING US INTO A CUL-DE-SAC, BECAUSE HERE WE'VE GOT THE END OF THIS TUNNEL, OR AT LEAST WHERE WORK STOPPED, BECAUSE BEYOND HERE IT'S JUST NAKED, HEWN ROCK.

GIVES YOU SOME IDEA OF THE CONSTRUCTION PROCESS.

IMAGINE HOW DANGEROUS IT MUST BE WORKING IN THAT ENVIRONMENT.

VERY DANGEROUS JOB.

NARRATOR: ONLY 16 OF A PLANNED 40 TUNNELS ARE COMPLETED BEFORE THEY ARE CALLED INTO ACTION...

BUT NOT IN A WAY HITLER ANTICIPATED.

AT THE LUFTWAFFE'S NERVE CENTER, ALLIED RADIO COMMANDS ARE INTERCEPTED.

RAISE THE ALARM!

[ALARM BLARING] NARRATOR: WHILE THE ALARM IS SOUNDED IN LUFTWAFFE COMMAND, GUNNER HUBERT WOLF IS STARTING HIS DAY.

MAN AS WOLF: AT 6:30 A.M., I TOOK MY FIELD GLASSES TO LOOK OUT TO SEA, AND WAS SHOCKED.

THERE WERE HUNDREDS OF SHIPS.

ALARM!

THE ALLIES ARE HERE.

[SIRENS BLARING] MAN AS WOLF: THERE WAS A HOWLING OF SIRENS.

ALL MEN TO FIND THEIR POSITIONS.

THE ALLIES ARE HERE!

MAN AS WOLF: EVERYBODY RAN TO THE GUNS, AND MADE THEM READY FOR FIRING.

WE FEARED AN ATTACK ON ALDERNEY, EITHER FROM SEA OR AIR.

THE TENSION GREW GREATER AND GREATER.

THEN I LOOKED TOWARDS THE SKY, AND SAW 300 AMERICAN BOMBERS ON A DIRECT APPROACH FROM THE NORTH, TOWARDS ALDERNEY.

WE HAD NEVER SEEN SO MANY BOMBERS BEFORE.

AND OUR FEAR BECAME ALMOST UNBEARABLE.

IF THEY WOULD DROP THEIR BOMBS ON THE ISLAND, WE WOULD ALL BE FINISHED.

THEY'RE GOING PAST.

MAN AS WOLF: AS IF BY SOME GHOSTLY HAND, THE PLANES TURNED TOWARDS FRANCE.

OUR COMRADES OVER ON THE OTHER SIDE DIDN'T HAVE THE SLIGHTEST CHANCE.

HOLLAND: IF THERE'S ONE POINT THAT KIND OF ILLUSTRATES THE JUST ENORMOUS FOLLY OF ALL THAT ENGINEERING EFFORT ON THE CHANNEL ISLANDS, IS D-DAY ITSELF, BECAUSE IT'S SUDDENLY THE CHANNEL ISLANDS ARE COMPLETELY BYPASSED.

NARRATOR: WHILE WOLF'S COMRADES ON THE NORMANDY BEACHES FACE AN UNPARALLELED ONSLAUGHT, SOLDIERS ON THE CHANNEL ISLANDS LOOK ON, HELPLESSLY.

THE GERMANS SUFFER MASSIVE CASUALTIES ON D-DAY.

SUDDENLY, THE GUERNSEY TUNNELS FULFILL A VITAL ROLE.

POLLARD: WITH D-DAY, THE PICTURE CHANGED DRAMATICALLY, AND SO DID THE USE OF THIS FACILITY, AND AT THAT POINT IT BECAME A HOSPITAL, AND THEY SHIPPED IN WOUNDED SOLDIERS FROM FRANCE.

AND THESE CHAMBERS, AND THERE ARE DOZENS AND DOZENS OF THEM, BECAME HOSPITAL WARDS.

AND, LOOK, ON THE FLOOR HERE, YOU CAN EVEN SEE THE IMPRESSIONS WHERE THE FEET OF THE BEDS ARE PRESSED INTO THE SURFACE.

YOU'VE GOT ROW, A ROW HERE AND A ROW HERE, WITH A NARROW GAP JUST UP THE MIDDLE, AND IT GIVES YOU SOME IDEA OF HOW MANY MEN WERE IN HERE.

UPWARDS OF 800 PATIENTS.

NARRATOR: AUGUST 12, 1944.

THE ALLIES SWEEP THROUGH FRANCE AND ARE CLOSE TO LIBERATING PARIS.

[WOLF SPEAKING GERMAN] NARRATOR: ISOLATED FROM THEIR ARMIES, GUNNER WOLF AND HIS MEN ARE STILL WAITING FOR THE WAR TO ARRIVE.

[SPEAKING GERMAN] MAN AS WOLF: NOTHING HAPPENED.

OUR DAILY LIFE AND ROUTINE WENT ON LIKE BEFORE D-DAY, WAITING TO BE ATTACKED, OR PERHAPS NOT.

BUT ONE DAY, THE BRITISH BATTLESHIP "RODNEY," POSITIONED CLOSE TO FRANCE, AND OUT OF SIGHT TO OUR GUNS, FIRED OVER 70 SHELLS ON ALDERNEY.

[EXPLOSION] SEVERAL LANDED VERY CLOSE TO US.

OUR LIVES HAD BEEN SAVED BY JUST A FEW FEET.

NARRATOR: DESPITE CREATING THE WORLD'S MOST FORTIFIED ISLANDS, IN A BITTER IRONY, HMS "RODNEY"'S PLANNED ATTACK ISN'T DETECTED BY THE NAZIS.

HITLER'S MEGAFORTRESS FAILS ITS ONLY MAJOR TEST.

AS THE ISLANDS REMAIN ISOLATED, BOTH GERMAN TROOPS AND THE ISLANDERS BEGIN TO GO HUNGRY.

GUNNER WOLF AND HIS MEN HAVE TO FORAGE FOR FOOD.

MAN AS WOLF: NOT KNOWING HOW LONG THE WAR WOULD GO ON, LACK OF FOOD BECAME OUR MAJOR PROBLEM.

WE TRIED ALL KINDS OF WAYS TO SURVIVE, BY COLLECTING STINGING NETTLES AND FALLEN APPLES.

NARRATOR: FINALLY, 11 MONTHS AFTER D-DAY, ON MAY 8, 1945, CHURCHILL DECLARES THE WAR OVER IN EUROPE.

ONE DAY LATER, AFTER 5 YEARS OF OCCUPATION, THE GERMANS SURRENDER THE CHANNEL ISLANDS ONBOARD A BRITISH DESTROYER.

IN HIS FINAL REPORT, COUNT RUDOLF VON SCHMETTOW IS DAMNING OF THE ENTIRE ISLANDS PROJECT.

MAN AS VON SCHMETTOW: IN MY OPINION, THE SUPREME COMMAND ATTACHED AN IMPORTANCE TO THE ISLANDS THAT DOUBTLESS EXCEEDED THEIR VALUE.

EXTRAORDINARILY STRONG FORCES WERE COMMITTED AND BOUND HERE.

THE REASONS FOR THIS HIGH VALUATION HAVE NOT BECOME KNOWN TO ME.

NARRATOR: AFTER THE WAR, GUNNER HUBERT WOLF BECAME A SUCCESSFUL ENGINEER, AND RECENTLY RETURNED TO ALDERNEY TO FIND HIS OLD FLAK POSITION.

THERE'S NO QUESTION THAT HITLER DOES GET OBSESSED WITH DEFENDING POINTS THAT HAVE BEEN TAKEN.

THEY'VE BUILT ALL THESE DEFENSES, THEY'VE BUILT ALL THESE TUNNELS, THEY'VE BUILT ALL THESE ANTI-INVASION DEVICES ALL OVER THE PLACE, AND IT'S UTTERLY, UTTERLY POINTLESS.

IT COMES TO NOTHING.

THEY'RE NEVER, EVER USED.

NARRATOR: SOME OF THE BEST-PRESERVED MEGASTRUCTURES IN EUROPE NOW STAND ON THE CHANNEL ISLANDS AS A LEGACY OF NAZI OCCUPATION... AND A WAR THAT NEVER ARRIVED.