A stratovolcano located in the south of Iceland, with a long history of charted activity and a rich mythology attached.

A cave network located at the southernmost tip of mainland Greece was once believed to be an entrance to Hades.

This mysterious underground cave in Shropshire dates back to the 18th or 19th century.

For centuries no one knew there were hundreds of bones and precious artwork hidden beneath this Swiss church.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

A monument to Lenin has been transformed into a statue of everyone's favorite black-helmeted, fool-choking Sith Lord.

Hundreds of dwarf beeches create an unusual, haunting forest in the north of France.

Hideout of thieves, monks, and goat-footed gods.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

This ancient Roman prison is decorated with an upside-down cross not as blasphemy but as saintly tribute.

This Italian ski resort rose to fame when Benito Mussolini was held prisoner there and then rescued by the SS.

After an epic flood washed away its enslavers, this city has been part ghost town, part cultural wildcard for the past three centuries.

See just what life was like in a 19th-century prospecting town.

Hundreds of hopeful gold miners came here to get rich, but only two years later the small town was deserted.

South Korea's love of the silly photograph is on full display at this goofy collection of trompe l'oeil paintings.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

This ghost town was once a cult-like religious utopian settlement.

A shady solar power system that couldn't hold up to the harsh desert conditions.

The remains of this early 20th century refinery loom on a mountainside like a graffiti-covered fortress.

This lava formation earned its whimsical name from the log-like formation of it stones.

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

An underwater city for the dead.

This sword isn't waiting for a king to pull it out. It was placed there by a saint.