A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

Part bookstore, part café, and part forest.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

Budapest's Communist-era statues, banished to the suburbs.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

Berlin's old airport.

A 30-acre garden inspired by the principles of modern physics.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

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

An ingenious Dutch land art project uses grass ridges to cut airport noise pollution in half.

“And the Lord said unto Johan, build for thee an ark for the end of the world is approaching.”

The bridges portrayed on EU currency aren't fictional anymore.

Incredible labyrinth of man made caves.

This miniature take on the Kremlin is one Dutch man's retirement project.

A true Valhalla for cactus and succulent lovers.

A market built atop boats is one of the few floating holiday markets in Europe.

This museum inside Amsterdam's largest cemetery explores how people deal with death.

Invisible bridge parts the waters, invoking biblical images and preserving the ominous feel of an ancient moat.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

Hidden within a Netherlands crater is a stone bed that lets those who lie in it see the sky as a curved surface.

A Portuguese Jewish cemetery filled with stunning grave monuments that date back to 1614.

A beautiful maze marks where three countries meet.

Peek through a transparent pyramid and drink in the mountain made of books.