A site where “the ravages of the war are more striking…than any other place in contemporary Spain.”

This odd Chilean waterfall-cano hotel must be entered via a rope bridge.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

A coastal rock outcrop with mysterious inscriptions variously attributed to Native Americans, Portuguese, Phoenicians, Norse, and more.

Native Americans built this circle of stones, which was used to predict astronomical events.

Mysterious ancient boulder carved with petroglyphs in the mountains of Western North Carolina.

Ancient human, animal, and geometric figures drawn in the earth.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

America's oldest archaeological site or a muddled case of wishful thinking.

Virgil's many-mouthed gateway to the underworld.

Steaming blood-red hot spring from hell.

A deadly ancient portal to the underworld.

According to one local tradition, the entrance to the Voodoo underworld can be found in New Orleans through seven gates scattered throughout the city's French Quarter.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

The ancient settlement attracts tourists from all over looking to learn about the Chinese vision of the afterlife.

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.

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

A gregarious Ohio resident has been building his whimsical temple to peace for decades.

One of the largest collections of holy relics in the country.

A collection of Witchcraft artifacts and occult paraphernalia started by the leader of the Long Island Coven.

Three small rooms at the back of the “official” church of London's clowns.

This small cemetery is all that remains of Atlanta's first Black communities.

Tour the sci-fi-esque reality of governmental disease management.