Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

An exquisite tunnel of cascading flowers.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

World's first "penitentiary," meant to be humane, drove men insane.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

An emerald-green grotto just a short trip from Austin.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

On Japan's Tashirojima Island, cats are king.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

A six-ton, 12-foot-tall concrete prairie dog is touted as the largest in the world.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

One man's quest to save his town with a trail of record-breaking sculptures.

Devilish landscape, once cinema home to giant alien bugs, now derelict roadside attraction.

This giant meditative chakra sits peacefully in the Flathead Valley of western Montana.

Three generations of intrepid collectors display their curious artifacts in a homemade museum right next to the caves they discovered.

The remote outlaw hideout of Jesse James, Butch Cassidy, and the Sundance Kid.

See just what life was like in a 19th-century prospecting town.

This amazingly preserved Gold Rush town is a historian's dream.

The last physical evidence of the Lewis and Clark trail is one of their autographs etched into this giant rock.

Native Americans built this circle of stones, which was used to predict astronomical events.