An illegally built ramshackle mansion tucked in the middle of Brooklyn is now being turned into condominiums.

This neo-Gothic former auto showroom is one of the few remaining reminders of Brooklyn's "Automobile Row."

A cabin completely covered in coffee mugs, where visitors are welcome to leave one of their own—if they can find an empty nail.

The mental institution where Van Gogh created some of his most famous work now allows guests to walk in the artist's footsteps.

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

Stroll through retro Paris while shopping for old postcards and discarded doll heads.

This bridge was constructed from the rubble of the infamous Bastille.

A grotto-like lodge decorated with gilded mosaics, rocks and a noisy waterfall was the setting for the most sumptuous pleasure house of 1900s Europe.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

France's national museum of scientific and industrial instruments.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

The oldest stone house in Paris was built by its most famous alchemist.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

A mechanized clock where a man fights off a dragon, crab, and rooster.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

This little-known relic crypt holds stolen parts of a Roman Empress.

A huge resale shop for the cast-offs of the film & television industry.

Check out the underground party scene at the "Burning Man of Brooklyn."

Two community gardens under the elevated subway lines on a very busy commercial strip in Bushwick.

Cambria's most unique B&B features creative surroundings and fantastic food.

A house built from trash known as the poor man's Hearst Castle.

One poet's handmade, anachronistic home.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.