This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

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

A crumbling hospital from the 1850s on Roosevelt Island.

Most-visited and most-photographed slot canyon in the American Southwest.

An emerald-green grotto just a short trip from Austin.

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

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

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

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

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

Non-profit time travel mart sells goods you would need for a trip through the fourth dimension.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

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

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

The taxidermied remains of Charles Dickens' pet raven, which helped inspire one of Edgar Allan Poe's most famous poems.

Where America's first doomsday cult awaited the end of the world.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

A rare view of a preserved Victorian science museum.

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

This Little Rock legend has survived decades of rowdy crowds, three fires, and a zombie wedding.