An abandoned NSA listening post on Berlin's "Devil's Mountain."

The remains of an idyllic small town built for the film 'Big Fish' still stand around a rundown main street.

Rustic natural hot springs in the deciduous rain forest.

This 16th-century monastery has been turned into a surrealist architecture compound.

Oregon's unexpected high desert, displaying layers of time in a colorful show.

Extraordinary sculpture garden created by an eccentric English poet.

The largest drain hole in the world.

Just a few miles from downtown Atlanta is a trail covered in a crazy collection of outsider art.

A late sculptor's last project was to turn this abandoned cement factory into a castle-themed amusement park.

San Francisco Bay's ghost town.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

This former tuberculosis research hospital endeavored to cure the dreaded disease with fresh air and positive attitudes.

This floating cinema brings new meaning to the phrase "going out" to the movies.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

A once grand hotel is being retaken by the wilderness it once capitalized on.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

This odd Chilean waterfall-cano hotel must be entered via a rope bridge.

In paradise, feral pigs have claimed an island all to themselves.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

Experience park where visitors are told to expect the unexpected.

A piece of outsider public art accompanied by a strange urban legend.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.