A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

2300-year-old Roman road connecting the empire.

The yawning maw of this pagan visage is said to bite off the hands of liars.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

Metro station with a claim to rock n' roll fame.

Cold war icon and onetime "hole" in the iron curtain.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

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

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

The most visited, and possibly most controversial, museum in Germany.

A huge wooden clock that is so beautiful its creator was forcibly blinded.

A merchant court dedicated to the fictitious King Arthur is heavily adorned with bizarre Renaissance art.

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

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

One of Ireland's most infamous prisons for rebels including men, women and children.

Communism's topsy-turvy effect on Poland has been brought to life in this wacky tourist trap.

A mysterious emblem tucked in an small alleyway is actually the coat of arms of a heroic medieval family.

These rare statues are one of the few remaining material witnesses to Old Prussian culture.

A floundering Polish shipyard was once the soul of the Solidarity movement that capsized communism.