One of the highest emergency huts in the world has been waiting almost a century to give imperiled climbers a place to lie down.

A castle-like sea fort from the 17th century is now a museum to oyster farming.

The home of one of America's most wealthy industrialists is now a historic site that remembers a more decadent time in the country's history.

The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.

A fake town founded by Western movie stars is now becoming a hip desert community.

This jam-packed Singapore antique museum preserves the fading remnants of a uniquely mixed culture.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

This colossal war machine is now a living museum dedicated to underwater warfare.

This stream-carved gorge has inspired poets, hidden smugglers, and trained soldiers, all without losing its beauty.

One of the most remarkable caves in all of Iceland was created by a once raging river of lava.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.

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

This brutalist monument is inscribed with 9921 names of Yugoslav partisans who perished during WWII.

An extraordinary "City of Caves" carved from solid stone.

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.

The world's oldest hologram gallery and the labyrinthine laser laboratory of a holography pioneer.

Go deep down into the earth to experience the world of Welsh coal miners.

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

One of America's oldest private membership libraries was long one of New Haven's best kept secrets.

The studio built by fascists in the hopes of "reviving the film industry" with the occasional propaganda film opportunity thrown in.

This once-grandiose behemoth of a monument from the socialist era now sits quiet and closed up.

The world's oldest surviving anatomical theater, where "the dead are pleased to help the living."