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

The plague quarantine island home to the alleged "Vampire of Venice."

Between Neo-Pagans and Neo-Nazis, these strange rock formations have a curious cult following and a very strange history.

This ghost town in Belgium will lose its street art when it ceases to exist.

A memorial for a young woman and her ghost, which are claimed to have caused countless deathly shipwrecks.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

2300-year-old Roman road connecting the empire.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

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

Legend has it that seven Anglo-Saxon kings were coronated on this stone, located in the appropriately-named town of Kingston.

An architectural oddity hides in plain sight on this iconic London bridge.

The ritual has been performed uninterrupted for nearly 700 years.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

Hear the quietest sound from across the dome.

An unusual round church in London with a Templar past.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

This bridge was constructed from the rubble of the infamous Bastille.

135 bronze medallions mark a French meridian line which once rivaled the hotshot Greenwich timeline.

A mechanized clock where a man fights off a dragon, crab, and rooster.

France's most famous cemetery, with some of its most curious tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.