Though its celestial ceiling is impressive, the true star is the vast collection of French books.

This empty Victorian manse on Staten Island is said to be haunted but is actually a real life crime scene.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

Mysterious 500-year-old tapestries depict a unicorn hunt.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Sniff the Titan Arum's rotting flesh.

Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

A semi-scholarly approach to sex.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

A crumbling hospital from the 1850s on Roosevelt Island.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

Lavish royal estate punctuated with heated greenhouses.

This Belgian palace was long the domain of priests and aristocrats but is now being turned into an art commune.

This abandoned Belgian fortress is purposefully being left to nature.

The Devil’s own choice when he needs a drink in Brussels.

Nature is slowly overtaking this disused cemetery on the outskirts of Brussels.

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

A gallery specifically dedicated to the botanical illustrations of a remarkable traveling lady.

Classic game cookery takes center stage at what's widely considered London's oldest restaurant.

This artist's home turned gallery/museum preserves the creator's love of "Eastern" influences.

A Victorian natural history and ethnographic museum with wonderful turn-of-the-century, science-book-esque evolution displays.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

Eighty million natural history specimens call this gargantuan museum home.