A museum of carnival attractions where you are invited to ride the rides.

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

Abandoned railway line circling the city of Paris.

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

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Notorious artist squat renovated into legal studios.

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

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

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

This quiet, unassuming spot in Budapest was the birthplace of the bloody 1956 Hungarian Revolution.

One of Hungary's most influential places of learning is also home to one of the world's most beautiful libraries.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

300 years of pharmaceutical history on display.

The abandoned military base looks like a post-apocalyptic wasteland.

Legions of Roman soldiers bathed in this ancient spa complex under a Budapest transit station.

A forgotten graveyard lost in the tangles of an overgrown garden.

A collection of intricate sculptures so small they have to be seen through a microscope.

This Hungarian stilt village is built in a lake that never freezes over due to the power plant that that uses it as a cooling pond.

Hungarian mummies in beautiful painted coffins.

Sitting beneath an unremarkable residential building is a museum devoted to classic Pinball.

A museum in the childhood house of a medical pioneer.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

Museum dedicated to the terror regimes of Hungary.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.