A mysterious castle built as a monument to lost love.

When this test site was abandoned, they didn't even bother to take the rocket with them.

This military tunnel dates back to World War II and provides visitors with a little wartime adrenaline.

A cave on the Maryland border where civilians took refuge during the bloodiest battle of the Civil War.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

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

A 16th-century horror show built in a lovely Italian garden.

This wrecked ghost ship has been rusting on a Greek beach since the 1980s.

Cave on extinct volcano, once home to famous mathematician Pythagoras.

Thousands of rusting train cars have been slowly falling apart on the edge of Greece's second largest city.

The ruins of an abandoned medieval city where the last Byzantine emperor was crowned.

A quirky bookstore hidden beneath a sea of whitewashed Greek villas.

According to myth, Zeus himself was hidden in this cave to escape being eaten by his dad.

Cretean quarry suggests real-life site for ancient Greek myth of the man-eating Minotaur in his labyrinth.

A spectacular cave and a beguiling lake.

Monasteries on rock pillars, once accessible only by frayed ropes.

Hidden in a secluded Greek cove is a pristine beach marred only by the rusting smuggler's hulk stranded on its shores.

Perched on a spindly rock spire in a Greek archipelago, this lighthouse would make a perfect wizard's tower.

This abandoned Poconos resort is haunted by a history of kitschy romance and a violent fugitive.

Collection of trolley cars in the woods represent one man's attempt to preserve transportation history.

An abandoned stretch of highway, deteriorating next to the operational one.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.

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