Macabre astrological automaton clock dating to the late 1400s.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A giant bug impaled on a 75-foot-tall needle.

The Bauhaus-style former industrial complex is considered the world's most beautiful coal mine.

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

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

Descend into the tunnels to experience the life of a coal miner.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

This sprawling Belgian fort was once thought of as impenetrable but now it is simply an abandoned relic.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.