France's most famous cemetery, with some of its most curious tombs.

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

Egyptian Revival movie palace abandoned for decades and restored in 2013.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

The narrowest street in Paris.

If your school was decorated with trippy graffiti, served ambrosial coffee, and was frequented by mimes, it might have been similar to this groovy cafe.

A traditional American farmhouse plopped in the middle of a Piccadilly courtyard.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

Drink your espresso at a Victorian-era urinal in this underground-restroom-turned-coffee-bar.

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

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

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

A giant bronze coil of feces is both a tribute to doggie defecation and a reminder to pick it up.

A five-story homage to tea times past.

"Purveyors of traditional sweets and vintage treats."

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

London's most popular recording studio, located in the capital's East End, runs partly on solar power and has played host to some of the world's biggest acts.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.