Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

Go inside to really appreciate this 500-year-old technological masterpiece.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

This huge clock made of flowers and simple machinery was once used a political weapon.

One of the greatest boxers and humanitarians to ever live chose his hometown as his final resting place.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This psychedelic tourist trap is a leisurely descent into madness.

This hidden jockey “walk of fame” celebrates the winning riders of the Kentucky Derby.

The remains of this visionary community can still be found much as it was a century ago.

A former 19th-century tavern, famous for its peach brandy and honey concoction.

Eight rare Corvettes are swallowed up by a sinkhole in Kentucky's National Corvette Museum.

A local scoured more than 1,000 acres for stone to create his masterpiece.

These experimental weapons brought World War II to Nebraska as well as 26 other U.S. states.

These banned cigarette vending machines now sell little pieces of pocket-sized art.

You thought Santa Claus didn't exist, but it turns out you were wrong.

A 30-year-old Sycamore tree grown from a seed taken to the moon and back.

Fans of vintage Vegas, kitsch, and toy pony-based gambling now flock to a casino called The D.

This erect, phallic geological spire wasn't always named so domestically.

Other-worldly rock formations and ancient fossils abound in this unique stretch of Nebraska badlands.

An experimental, automotive replica of Stonehenge.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

Thanks to a loophole in property ownership, this alleyway has become a cacophonous street gallery.

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.