The experimental test tracks of a retro-futuristic monorail still stand in the French countryside.

Peeing dogs guard the Roman hunting goddess atop a fountain at France’s Château de Fontainebleau.

Climbing to the top of the cathedral's bell tower offers sweeping views of these medieval ruins.

No one knows who built this strange cave of worship or exactly why.

A medieval church built up to defend its village.

Even drowned in an ocean of toxic waste, the remnants of this Romanian village stand tall.

Hundreds of boat-shaped headstones fill this graveyard as part of a centuries-old custom with mysterious origins.

A preserved Nazi labor camp now has a Holocaust museum on site and memorials to the thousands that died while imprisoned at the camp.

A massive playground in the woods of Germany.

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

This East German military command bunker was ready for World War III.

This enchanting mountain plateau celebrates spooky local folklore.

This building’s ghostly exterior reflects its former lives as a prison, school, and funeral home.

On the grounds of a former estate in Burgundy stands an elaborate temple that is modeled after the first Tibetan Buddhist monastery.

The huge golden reliquary of a testicle-smashing saint.

A treasure trove of fine art is hiding inside this small medieval abbey in Gascony.

A museum dedicated to the Spanish occult in a town that was terrorized by the Inquisition.

One of the largest ossuaries in Spain is packed from floor to ceiling with bones.

This haunting location was featured in the final scene of a classic spaghetti western.

This Gallo-Roman sanctuary is dedicated to Serápis, god of the underworld.