It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

This ancient trail climbs the mountain where a Latin League cult worshipped Jupiter, its main deity.

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

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.

The world's largest wooden structure.

The final resting place of the great navigator, or maybe his brother.

Ancient snack bar of the Roman Empire re-opened.

Erotic art covers the walls of the largest ancient pleasure palace.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

This statue of a falling man commemorates a teenage martyr of the Hungarian Revolution.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

One of the world's tallest statues is also one of its most hated.

World's largest bell sits on the grounds of the Kremlin in Moscow.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

A medieval military street hidden beneath a charming French fishing village.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This massive blockhead sculpture hides an entire library.

Museum dedicated to "the man who moved the Earth."