A castle hand-built by a Spanish dreamer in the Australian tropical jungle.

Australian Lake set aglow by Noctiluca Scintillans.

An abandoned railroad tunnel is now filled with bioluminescent bugs.

An Australian lake whose pink hue defies scientific explanation.

The oldest stone house in Paris was built by its most famous alchemist.

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

Notorious artist squat renovated into legal studios.

Abandoned railway line circling the city of Paris.

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

The famous artist couple lived and worked here, in two different houses separated by a bridge.

A jaw-dropping "megalibrary" that turns book-browsing into a geometric adventure.

66,000 pieces of art, donated by one of the world's richest men.

Superstitious? Discover the witchy side of Mexico through its largest esoteric market.

Part bookstore, part café, and part forest.

Frida Kahlo's childhood home, now a museum of her life and works.

An island filled with hundreds of hanging, decomposing, decapitated dolls.

A portable, wooden replica (minus the hyphen) of Hamburg’s iconic crooked coffee shop.

Berliners converted a bombed-out, disused lot into a community-run urban farm with its own cafe and bar.

The most visited, and possibly most controversial, museum in Germany.

A slice of central Asia in the middle of Berlin.

Started as a kitchen garden, now the second largest botanical garden in the world.

A surreal museum of extraordinary industrial objects.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.