This ancient structure appears Roman, but was constructed during the 16th century and was utilized until 1911.

This crumbling medieval basilica once attracted pilgrims by the thousands to collect a miraculous dust that formed above the saint's tomb.

Replicas of Apollo's leonine stone guard cats still line a sacred row in Greece.

Legend says if you stick your thumb in the hole and it gets wet your wish will be granted.

A marvel of Byzantine engineering under the streets of Istanbul.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A sixth-century Byzantine cistern hidden below a modern carpet store.

A stunning gilt bronze relief denounced by Hitler as "degenerate art"—even though it was dedicated to the Nazi leader.

Eight naturally mummified bodies in glass coffins are housed in an underground crypt.

A modern museum dedicated to the fairytales and dictionary work of the Brothers Grimm.

This ornate Weser Renaissance house was also the home of an infamous witch hunter.

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.