Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Macabre astrological automaton clock dating to the late 1400s.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

This insurance company building reminds customers that witches, bears, and gnomes are out there, best be insured.

A subterranean house of worship carved right out of the bedrock.

This colorful artistic feature atop a Danish art gallery allows visitors to stroll through a rainbow.

A whimsical art tower at a Bavarian brewery includes a grotto for its mythical beer-brewing dwarves.

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

Rare karst landscape eroded from a flat seabed.

A 12th-century fortress containing some of Berlin's oldest buildings.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

Go surfing on this urban wave, "hacked" by local surfers.

A stairway to heaven, or to nowhere at all.

The footprint of a frustrated devil in Munich's Cathedral.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

Enter the cabin of a life-sized Hindenburg replica.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

Among the ostentatious rococo ornamentation of this church, an image of death cuts the life-thread.

The prototype for all Nazi concentration camps.

An old department store turned Nazi prison turned artist commune.