A set of ancient drawings in the desert of Peru that are so massive, many of them can only be fully seen from the sky.

The mortal remains of an estimated 70,000 people lie in the basement of a monastery in Lima, Peru.

A church of bones, decorated with 40,000 human skeletons.

Mummified monks and the accidentally interred, in a 17th-century crypt.

Europe's second largest ossuary wasn't discovered until 2001.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

This automated sculpture of two men peeing will spell out text messages with their micturition.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

The first museum in the world devoted to sexual gadgetry.

Macabre astrological automaton clock dating to the late 1400s.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

Baroque celebration of the end of the Great Plague of Vienna.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

The deepest metro station in the world.

One of the largest museums in Ukraine remembers the story of the German-Soviet War in iconic, brutalist style.

This derelict superstructure was a very important warning system for the Soviet military.

One of the most poignant ruins of the Chernobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

A reconstructed medieval gateway that was the magnificent entrance to the capital city dating back to 1037.

This attraction was abandoned after the Chernobyl disaster.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.