This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

Longest canal tunnel in the world, abandoned in the 1960s.

This ghost town was once a cult-like religious utopian settlement.

An abandoned swimming pool decays on the outskirts of Berlin.

A short distance from the Eiffel Tower is the final resting place of several of the city’s more well-known and interesting characters.

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

This museum houses an imposing skeleton army comprised of creatures great and small.

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

A series of abstract, silly sculptures represent the works of a great modern classical composer.

Dedicated to the art of hunting, with juxtapositions of contemporary art.

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.

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

How did a French journalist’s grave become the sexiest statue in the cemetery?

From lefty Jewish gathering site to hip cultural site in just 80 years.

This famous church is adorned by a mural commemorating the independence of Vatican City.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

A massive underwater sinkhole made famous by Jacques Cousteau.

It was once the base for a series of domestic terror attacks.

An old department store turned Nazi prison turned artist commune.

Come stay at a live-in art installation.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

Fall down the rabbit hole into a surreal journey of human consciousness "from ass to soul."

Concerts, art, offices, and a café in what used to be Berlin's first crematorium.

Once a path for Jewish funeral processions, this unassuming alleyway is rich in local lore.