The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Old Danish castle immortalized in Shakespeare's Hamlet.

Copenhagen's celebrated theme park and gardens.

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

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

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

An existential riddle in the world's largest ancient castle.

Countless grotesque faces stare out from this eerie Prague art wall.

Macabre astrological automaton clock dating to the late 1400s.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

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

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

This bell stars in a tragic love tale and is said to make wishes come true.

The Polish capital has had a deep connection to its guardian mermaid for almost a millennium now.

The discovery of an old wall led to the creation of this fascinating museum about the city in the Middle Ages.

One of the most breathtaking railways in Europe also takes one of the steepest climbs, from fjord to mountain plateau.

A favorite with sightseers, this Norwegian funicular provides easy access to a stunning view of Bergen and its environs.

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

2300-year-old Roman road connecting the empire.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

A small town Romanian cemetery filled with darkly humorous gravestones.

Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.