The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

The granddaddy of English geoglyphs dates back to the late Bronze Age.

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

This magical museum celebrates the life and work of a seminal children's book writer (and occasional spy).

The famous artist couple lived and worked here, in two different houses separated by a bridge.

The former home of the hard partying literary power couple is now one of the only museums devoted to their story.

A open air theatre built on a cliff by an eccentric British woman.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

"There's nothing there," and other lies the KGB told us.

These stark white cliffs were spat up by the sea and are slowly being retaken by it.

Berlin's old airport.

High atop a Mexican rainforest mountain, this ancient pyramid once drew pilgrims countries away.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

Dating back almost 400 years, the oldest public collection library in the United Kingdom was once the study hall of Karl Marx.

An ancient city exhumed from the depths of the ocean.

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.

Large Hadron Collider and the Birthplace of World Wide Web.