In the ruins of Glastonbury Abbey lies the alleged resting place of the legendary king.

The site of a mysterious pony massacre is rich with extraterrestrial conspiracy theories.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

Mozart's skull may be held in this collection, but definitive proof continues to elude scientists.

A museum dedicated to the former country.

The remnants of an archaeological camp stand within Tikal National Park.

Diego Rivera's massive tiled fountain and failed infrastructure project.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

The plague quarantine island home to the alleged "Vampire of Venice."

Discarded animal sculptures stand forgotten by an abandoned aquarium and water park in Bosque de Chapultepec.

The masses at this church incorporate enough moonshine and animal sacrifice that they are no longer recognizably Catholic.

This beautiful and unmissable little museum is full of fascinating artifacts from Mesoamerica's great civilizations.

This bridge over the River Cuale leads to a neighborhood that was once an escape for Hollywood's elite.

During its heyday, the massive estate boasted its own railroad station and post office.

This giant expressionist head crowns a museum devoted to a beloved Mexican leader.

Once a year in Pomuch, the dead are taken out for a cleaning.

This church devoted to Mexico's "dead saint" is a festive celebration of a formerly hidden religious figure.

One of the world's largest murals covers a large swath of homes in its hillside neighborhood.

Three sinkholes filled with warm, crystal-clear water reached by a horse-driven cart on an old train track through the jungle.

Huge hole looks down onto an underground beach populated with sea lions.

Psychedelic murals coat the inside of a nondescript research library.

A lake at the bottom of the ocean.

Inside this mountain lies several kilometers of breathtaking caves.

At least seven hues of blue and turquoise make this freshwater lagoon unique.