The world's greatest slide descends 18 stories from this looping mountaintop viewing platform.

This Parisian fountain is a little bit fantasy and a little bit nightclub.

These broken shards of ancient ruin may hide an ancient pyramid.

This beautiful, historic church looks like something out of a simpler past.

A vast, otherworldly collection of Buddhist stupas.

The world's oldest surviving anatomical theater, where "the dead are pleased to help the living."

This famed marionette theater and museum is bursting with imaginative string puppets.

This museum is rotten with a century of wax medical deformities.

At the very tippity-top of Europe is a cliff from which you can view the midnight sun.

A factory in Milwaukee where poop is reclaimed… and recycled.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

The most gigantic, swoony, intimidating trio of fingers in all of antiquity.

This ancient city - home to nine civilizations - is soon to be buried under 200 feet of water.

One of the largest necropolises in the world is home to a stunning array of historic Middle Eastern tombs.

The remains of what was the most important religious complex in coastal Peru for over a millennium.

One of Hungary's most influential places of learning is also home to one of the world's most beautiful libraries.

This cluster of little wooden huts once ground local farmers’ wheat into flour during the days of the Austro-Hungarian Empire.

A bathhouse from the second Islamic Caliphate decorated with frescoes of constellations, pleasure gardens, and naked ladies.

A tower built by an emperor for an antelope.

On rare days, this abandoned castle's gatekeepers open its doors, revealing the eye-popping splendor hidden inside.

The ghost town where the villagers refuse to leave.

A trio of giant wooden megaphones turn up nature's volume in this Estonian forest.

These phallic stone spires once served as Tolkien's Paths of the Dead.

An alien landscape on the banks of the Aegean Sea.