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

Paris' linguistic guide to the international language of, yes, love.

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

Abandoned railway line circling the city of Paris.

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.

Amsterdam's former hotspot for public executions and dissections.

An overgrown and largely forgotten cemetery lies hidden within the outskirts of Amsterdam.

A Portuguese Jewish cemetery filled with stunning grave monuments that date back to 1614.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

The attic of a four-century-old canal house hides a clandestine church.

The history and future of cannabis.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

A curious collection dedicated to human and animal anatomy and pathology.

Museum preserving torture methods from the past.

The world's only museum devoted to the wonders of fluorescence.

High Victorian fantasy created a fairytale castle out of a ruined fortress in Wales.

Stroll through Welsh history in a village of reconstructed structures.

The castle still holds traces of the abandoned Roman fort it was built atop.

A harem-inspired Moorish fantasy design in a Victorian-era Welsh castle.

An abandoned hotel in the highlands of Bali is shrouded in stories of ghosts, curses, and corruption.

Colloquially known as “piss alley,” this narrow street filled with tiny bars and barbecue stands looks like it was pulled straight out of “Blade Runner.”

A King Kong-like gorilla hangs from the top of this commercial building in Tokyo.