Natural cathedral designed by Italian artist Giuliano Mauri.

Living trees form the structure of an open-air palace.

This abandoned bridge to nowhere stands secluded in the woods of a Cleveland suburb.

It's unclear what caused the fire that led to this opulent hotel's demise.

The unedited photograph called "Bliss" has graced the screens of over a billion computers.

Ivy-covered Medieval tunnels cut through this charming town in France's Loire Valley.

The post-apocalyptic remnants of a bucolic town ruined by a plane crash.

A remote hilltop covered in giant monoliths haunts the Brittany countryside.

The haunting concrete remains of a Nazi pebble crusher can still be found in this small French commune.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

An abandoned amusement park hints at the twisted history of the Newfoundland Railway.

This museum in the tower of the oldest church in Gdańsk, is home to centuries-old time-keeping devices and the world's first pulsar clock.

This Communist-era residential block is one of the longest residential building in Europe.

This antique thermometer honors the creator of the first universal temperature scale.

A merchant court dedicated to the fictitious King Arthur is heavily adorned with bizarre Renaissance art.

These rare statues are one of the few remaining material witnesses to Old Prussian culture.

A huge wooden clock that is so beautiful its creator was forcibly blinded.

This 700-year-old structure is one of the most unique architectural and historic monuments in Gdańsk.

The site of the first battle of World War II.

This medieval castle was painted pink as part of a now-abandoned children's theme park.

A late-medieval Dutch castle with trick fountains in its whimsical water gardens.

No need to strap in for a "ride" on this walkable roller coaster.

This neighborhood of futuristic ball houses looks like an alien settlement in a science fiction film.

A million and a half tons of earth were used to create one of the world's largest land sculptures.