An alchemist's "magic door" stands in the middle of a Roman park.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

This disastrous New Jersey safari park saw animal attacks, escapes, and disease before being abandoned.

Disney's abandoned animal island is now an overgrown ruin that was almost the coolest attraction ever.

Civil War soldiers, captains of industry, and paupers all interred on historic grounds.

A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

Beneath the surface, something slithers. And if you find it, prepare to be slimed and glowing.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

Giftshop catering to cryptozoologists and anyone with a sense of humor.

The only remaining collection of flayed figures made by French "madman" Honoré Fragonard.

Weird wax anatomical models reside here, as do other anatomical specimens.

A haunting collection of the vanished and disappearing natural world.

"In the Dark" Restaurant in Paris offers dinner in complete darkness.

Inside a former cabaret, seven floors of erotic art.