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

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

Despite being considered a thoroughly American sport, basketball's oldest surviving playing field is found in the basement of a Paris YMCA.

In the best of all possible worlds, everyone will get a chance to see this statue in which Voltaire's heart is interred.

The oldest stone house in Paris was built by its most famous alchemist.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

A quirky and charming restaurant founded by artists.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

Dine on food tied to Viking history and legend at this subterranean Stockholm spot.

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

This grisly exhibit houses skeletons and weapons from a devastating 14th-century clash.

Vortex-shaped aquarium hosts Europe's largest school of piranhas and other ocean creatures.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

A novel collection of medical curiosities housed in an 18th-century surgeon training academy.

Bored potato-guarding Nazis etched their thoughts onto a brick storage building in Copenhagen's Meatpacking District.

This wonky bit of historical taxidermy is experiencing a second life online.

A king's bloodstained shirt is among the gruesome collection of artifacts displayed below Stockholm's Royal Palace.

Now a hotel, this former bank was the site of a robbery that spawned a psychological phenomenon.

It houses the remains of a 17th-century version of the Titanic.

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

Iron Age "bog person" preserved for over 2,300 years.

Displaced highlanders would take shelter from the wet Scottish climate under the large walled bridge at Glasgow Central Station.

Scotland still bears an enormous scar of its Roman past.

This stone was once used by druids to determine a person's innocence or guilt.