The castle still holds traces of the abandoned Roman fort it was built atop.

This eclectic antique shop is home to the taxidermy remains of a celebrity lion named Simba.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

This grave in a ghost town cemetery marks the death of a witch on a day that never happened.

An abandoned observatory in the middle of the Illinois prairie.

Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

The history of funerals and funerary customs.

In the loving memory of a tragically deceased role-player this Illinois park is decked out with both dungeons and dragons.

Few of the many visitors to this resort town know of its hidden Maya ruins.

The ruins of an important pilgrimage destination for worshippers of a Maya fertility goddess.

A flooded Mexican cave that hides a river beneath the water.

An ancient system of freshwater caves filled with animal bones, including that of species long-extinct.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

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

The gutted remains of this Estonian mansion are a monument to a tragic love.

This Central New York ghost town was once a prosperous railroad community.

An abandoned castle owned and ignored by Masons carries a cursed history.

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

Abandoned castle was once a grand example of Russian privilege, built exclusively to win a frivolous bet between noblemen.

This centuries-old hotel hides a network of secret cellars and passages once used by smugglers.

Named for the biblical warrior, the largest castle in Israel actually dates to the Middle Ages.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

A curious memento mori hangs in the magnificent Cathedral of Segovia.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.