These caves secretly held national treasures during World War II.

Legend says this sacred tree was a gift from goddess Athena.

There are many Byzantine-era churches still standing in Athens, but this is the only one with a 2,500-year-old column rising through its roof.

This striking sculpture of Icarus honors Greece's fallen flyers.

This German fountain of a legendary apple wine-loving drink thief will spit on you.

This gateway to subterranean Hanover plays jazz, pop and rock to surprised passersby.

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

This former steel and coal plant is now a neon-lit industrial fantasia.

Free public park and gardens filled with peacocks and peahens.

A view-altering observatory at the University of Texas.

Visitors can walk over the largest concentration of Columbian mammoths to have died from one event.

Cockroach Museum features roach celebrities and live hissing cockroaches.

A quirky collection of old chairs fills a random vacant lot in suburban Texas.

Wooden pathways run through this rocky landscape, which legend says was created when a dwarven king pulled down his own castle to stop raiding giants.

Along the banks of the River Rhine lies a park that seems unassuming, but beneath the surface lies a long and fascinating history.

This German bone house contains the remains of some 20,000 souls.

This remarkable parking garage in Darmstadt has lived several lives and still contains remnants of its World War I past.

The zoological collection at the Hessisches Landesmuseum hosts some of the world's oldest habitat dioramas.

A former Nazi lookout tower with a magnificent view of the Rhineland.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

An ancient pagan site swirling with legends in the foothills of Franconian Switzerland.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

The 1852 novel "Uncle Tom's Cabin" lends its name to a subway station, a street, and several shops on the edge of Berlin.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.