An open-air museum in a mountain valley features works designed to blend in with—and disintegrate back into—their natural surroundings.

This former fascist summer camp was abandoned for decades.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

An extraordinary collection of 18th century anatomical waxworks.

Eighteen mummies have stood guard behind the altar of this tiny church since 1833.

Geothermal waterfalls in Tuscany.

A 16th-century horror show built in a lovely Italian garden.

This immaculate and historic water garden culminates in a massive stone dining table with an inset fountain for chilling the wine of the Cardinal's guests.

This Italian stadium makes liberal use of fascist statuary to evoke classical sporting arenas.

The "Prussian Versailles" that is as glorious today as when it was built.

Solar observatory doubles as a daring display of Expressionist architecture, much to Einstein's chagrin.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

An eerie, derelict amusement park in Berlin.

This little museum is making sure that the art and history of the graffiti sticker is not scraped from history.

A collection of abandoned typographic signs from Berlin and beyond.

A surreal museum of extraordinary industrial objects.

An old department store turned Nazi prison turned artist commune.

Medical history with an amazing, if frighting, collection of wax diseases on display.

A completely underwater art museum sends a stark message about humans' impact on the environment.

A quarry cum sculpture park where the works of art are chiseled into the very walls.

The birthplace of the builder of the Statue of Liberty is now a museum dedicated to his work.

700 iron sculptures crammed into a Mediterranean park.

One architect's organic, human-centric design has been fully realized in this alien art house.