This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

Christ's blood preserved in a Belgian town.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

This towering church is home to a world-famous organ and a treasure trove of medieval art.

This old KLM airplane cut into three parts was transformed into an eclectic airport gift shop.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

Tiny castle in the middle of the Rhine made you pay to pass.

Stare out over the lagoon and beyond from this 10th-century campanile on the island where the city of Venice began.

According to tradition this is the oldest church in Venice, but its actual age is a mystery.

Two stone columns flank the grand Venice square, but there were supposed to be three.

The small peaceful island off the Venice tourist circuit is where the city began more than 1,500 years ago.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

Next to the Leaning Tower of Pisa is a cemetery home to ancient sarcophagi and disturbing murals.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

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

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

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

The Neapolitan Cult of the Dead still cares for the skulls at this mini-Fontanelle.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

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

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