This 8th-century Bavarian monastery is home to an exquisite Baroque-era library.

This ancient ruined monastery has been destroyed by fire so many times that it seems like God hates it.

It's always summer at the beach inside this former airship hangar.

A German apartment building hosting as many trees as human occupants.

This Nazi-built amphitheater was constructed on a sacred mountain site used by various German cults.

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

A long spiraling walkway winds through the woods, and around a copper beech tree at the center.

Between Neo-Pagans and Neo-Nazis, these strange rock formations have a curious cult following and a very strange history.

This historic stone bridge has an entire neighborhood clinging to its sides.

Soaring over 6,000 feet in the Bavarian Alps, this beer garden was once Hitler's 50th birthday present.

This "floating railway" is one of the world's oldest monorail systems.

A striking 12th-century-style castle built on the edge of a cliff.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

The castle was reconstructed to fit Kaiser Wilhelm II's romanticized vision of the Middle Ages.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

This centuries-old Italian chapel hangs midway down a sheer cliffside.

A former top secret nuclear fallout shelter now operates like a hotel stuck in the Cold War.

Underneath the city that invented pilsners are a series of historic tunnels that have been storing beer for centuries.

Folklore says this medieval fortress was plopped atop a portal to hell to trap the demons below.

Enormous sandstone towers loom within a Czech forest.