Underground hospital complex constructed by slave laborers during the German occupation of the Channel Islands.

An 800-year-old island castle in Guernsey's main harbor.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

The Lone Star plaque hangs in a bombed-out bunker in Normandy to honor a Texan colonel's heroic actions on D-Day.

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

Remains of the artificial harbours invented for the Allied invasion of Normandy can still be seen at sea.

This bridge was constructed from the rubble of the infamous Bastille.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

This massive sculptural work outside of Paris was four decades in the making—and it's still not quite complete.

In 1927, a biplane disappeared while attempting to complete the first non-stop transatlantic flight between Paris and New York City. This memorial stands at the last place it was seen.

This bunker in northern France was built by Nazi German forces with the intention of launching up to 50 V2 rockets at London each day.

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

Locals call it the "Give Peas a Chance" bridge because of its distinct graffiti.

The largest stone circle in the world has ended up bringing up more questions than it has answered.

This hilarious English intersection is an automotive whirlpool.

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

This bridge is the first to be made entirely from iron, but designed like it was still made of wood.

At 1,732 feet above sea level, this spectacularly isolated yet surprisingly bustling bar is the highest pub in Britain.

The dramatic remains of an abandoned farmhouse sit high on the edge of a remote hillside.

A steep and winding road in the Yorkshire Dales passes by these deep natural potholes.

One of the oldest and certainly best preserved Cistercian abbeys still in existence.

Astonishing rock formations dot the Brimham Moor landscape.

A long, winding trek rewards you with a gorge so captivating it inspired a painting in the Tate.

Harry Potter once visited this massive limestone cliff, which was carved by an ancient glacial river.