A medical facility that has been kept frozen in time.

A stunning, abandoned limestone quarry in southern Indiana provided the stone to erect the Empire State Building.

The longest navigable underground river in the United States is home to countless blind and albino animals.

A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

Celebrated in poem, this tiny hidden cemetery has a big and grisly history.

The elegant structure of this 19th century railroad bridge creates an illusion of infinity.

England’s ancient oak tree has such an impressive girth, people have been hosting parties within the hollow trunk for centuries.

Constructed during the 7th century this is one of the oldest largely intact Christian churches in England.

It's believed Matilda Fitzwalter's life was the basis for the famed literary figure.

An English artist has turned an unassuming ex-council house into a time-lost house of mystery.

This lonely bronze walrus celebrates a character in a Lewis Carroll poem.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This workshop and small museum is dedicated to tiny, delicate figurines that began as a subversive craft after the French Revolution.

A small island that was once a key Axis fortification during World War II.

A treasure trove of fine art is hiding inside this small medieval abbey in Gascony.

A total of 22 tiny bridges cross this canal of the Yvette River, forming a unique trail.

A precariously balanced goose-shaped boulder with a dark legend.

Before this bridge was built people had to wait for the ferryman, an annoyance that, the story has it, gave the town its name.

A place to see how French aristocrats lived in the early 1900s.

Peeing dogs guard the Roman hunting goddess atop a fountain at France’s Château de Fontainebleau.

A unique museum tells the story of the day-to-day life of World War I soldiers.

An image of the legendary saint stands in the shadow of a cathedral she liberated.

This secret cemetery where no flag is allowed to fly holds the bodies of American soldiers convicted of heinous crimes during WWII.

This statue honors the thousands of Allied avians that served and died for France during World War I.