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

Explore the complex ecology of this multifaceted nature preserve by riverboat.

A 12th-century fortress containing some of Berlin's oldest buildings.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

Thirty creepy ghosts now inhabit this decaying 14th-century church.

This unique Renaissance castle was turned into a home for Nazi occultism.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

Slaughterhouse Five opens its dank doors to fans of Kurt Vonnegut.

An intricate and amazing house built by architect Karl Junker.

A spiral staircase twists to the top of this unusual Czech lookout tower.

The 1936 Summer Olympics site is a crumbling remnant of sportsmanship and a history its host country would like to forget.

These 18th century gardens tell a rocky story of the son of Odysseus.

This Gothic-style church is reputedly built atop the remains of one of Jesus's apostles.

The remains of the left arm of the levitating philosopher-saint are kept in a 13th-century Neapolitan basilica.

A quaint Russian village in the middle of a German metropolis.

Striking occult iconography on a medieval German church.

A sprawling Baroque park with 300-year-old hydro-pneumatic waterworks.

This German museum is devoted to all aspects of grave culture from headstones to coffins.

The history of German architecture is explored across this fairy-scale mini-city.

The architect of this fanciful complex called it an "oasis for humanity and nature in a sea of rational houses."

The medieval institution is home to the precious treasure stolen in World War II in one of the greatest art thefts of the 20th century.

The largest brick bridge in the world.

"The most colorful grottoes of the world.

Living trees form the structure of an open-air palace.