The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

Once the foundation for a mansion, these ruins now offer amazing panoramic coastal views.

The remains of a century-old mansion that met a fiery demise years after it was deserted.

Crumbling ruins mark the site of a couple's grisly murder in the woods.

On the Oregon coast there is a natural hole that seems to be draining the sea.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

World's first "penitentiary," meant to be humane, drove men insane.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

Tucked in the back of this amazing antique store is an important piece of medical history.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A crumbling hospital from the 1850s on Roosevelt Island.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

World's largest collection of serial killer artwork and other macabre exhibits.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

A psychedelic labyrinth on the San Francisco bay.

An artsy hidden staircase leads to breathtaking views of San Francisco.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.