A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This massive library holds what was once the largest book collection in the world.

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

The sign at the garden gate reads: "These Plants Can Kill."

One fisherman has used his love of pebbles and shore to create a crazy garden of rocky art.

This tunnel entrance is built to resemble a grand castle but no one is quite sure why.

The rotting skeleton of a shoreside fun fair that was destroyed by fire and storms still haunts the Brighton ocean view.

Decrepit Victorian public lift is a white-knuckle ride.

Regency-era excess on the English Coast.

Neon signs that grace the windows of Bergdorf Goodman's and Tiffany & Co. come from this studio in Brooklyn.

London's largest outsider art museum.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

The final resting place to 300 Victorian-era pets hides inside the city park.

This wildly-tiled artist's palace is a living and growing account of the creator's life, loves, and labors.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

A tongue-in-cheek arcade where the games are based on everyday life.

Salute the leader of the proletariat.

Prove you deserve to be fed by Kenny Shopsin.

Leaf through over 30,000 artists' sketchbooks in what may be the world's largest collection of doodles

The oldest surviving synagogue in New York City is now a soaring art space.

A masterpiece of LGBT art has been restored in what may now be the most valuable restroom in America.

Nondescript elevator doors open to reveal a stunning, surreal world.

A New York garbage depot holds a secret collection of weird and wonderful refuse.