A Jenga-style cylindrical tower of books that appears to go on forever.

A church of bones, decorated with 40,000 human skeletons.

Two stunning 17th-century libraries and a cabinet of curiosities.

An abandoned Soviet-era mining town in the mountains of South Kazakhstan.

Rusting ships sit in a desert where a sea used to be.

Submerged trees jut ghost-like out of an idyllic turquoise mountain lake.

Two standing giants remain as a tribute to Luxembourg's metallurgical past.

This Luxembourg cave is covered in cryptic looking marks left by mining activity.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

This noble mash-up in eastern Luxembourg is part Medieval, part Renaissance, all castle.

This tri-part waterfall is a little bit of fairytale beauty in the heart of Luxembourg's Little Switzerland.

Once the local rulers had gone these enchanting ruins housed common folk in an almost real life fairy tale.

This bakery and museum offers tours of the tastes and mythology of Aachen's signature spice biscuit—just don't ask for the recipe.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

This small electronics museum is full of whirring, humming, clicking ephemera.

Where royalty waits in the height of luxury.

A condensed piece of China floating in a Dutch harbor.

Some 80,000 Delft Blue tiles line the inside of this Amsterdam walkway.

A tiny house showcases the busy life of a local gnome.

Nestled in the woods lies this land art project: a hybrid between park, maze and natural monument.

A giant yellow phallus sculpture hidden in the gardens of the Museum Boijmans Van Beuningen.

Portraits of musicians line Oude Binnenweg, the jazziest street in the city.

It's forbidden to dig within this ancient Roman fort hidden beneath a playground.

This unique sculpture proved invaluable when it saved a train from careening off the tracks.