The ruins of a bombed medieval village memorialize the destruction of the Spanish Civil War.

An architect transformed this abandoned cement factory into his castle-like workshop.

Abandoned tunnels dug for the once-thriving sea salt industry on the coast of southern Spain.

This huge abandoned fortress hidden inside a mountain holds a world of subterranean secrets.

A Franco-era dam flooded (almost) everyone out of this centuries-old Aragonese town.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

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

This Navarrese cave's history of witchcraft and pagan ritual is not just embraced, but recreated each year.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

During an annual Catholic feast in this tiny Spanish village, men dressed as devils leap over rows of babies to cleanse them of sin.

A network of hundreds of interconnected wineries in caves hides under the town center.

This one-room cabin where the young colonel slept during the French and Indian War.

Despite violent work crews and massive delays this abandoned canal tunnel was built to last into the modern day.

In which a local geological marvel becomes a quaint roadside attraction.

The oldest farmer's market in America is so ancient it was approved by the King of England.

Hellam Township is reputed to feature seven remote gates, which when passed through in the right order, open an entrance to hell.

A toxic ghost town sitting atop a massive coal fire.

These tourist trap caverns are said to be the former home of a legendary Pennsylvania Hermit.

These strange large stones served as a campsite and lookout post for generations of Native Americans.

The record holder for the world’s largest peach.

The cruel trial of a 13-year-old boy inspired the creation of this now abandoned reformatory.

An abandoned village that doubled as "The Hunger Games"' post-apocalyptic wasteland is up for grabs.

A historic covered bridge, only one of two remaining in North Carolina.

An unfinished rail tunnel that has since been used to house cheese and bats.