This recently rediscovered Civil War-era submarine was the first to ever sink an enemy ship.

One man's extraordinary topiary garden in a small South Carolina town.

According to local lore, this narrow passageway through two large rocks was accidentally created by the devil himself.

This set of rickety spaceships are prepared to give alien travelers a place to relax and go to the bathroom.

A huge musical instrument played by the ocean.

A tribute to the twin ideals of religion and patriotism, built by a Catholic priest from rocks, glass, and innumerable found items.

A wonderland of caves in eastern Iowa.

An underground wonderland in Iowa.

Elaborate hand-carved wooden clocks two brothers made in their spare time are on display at this handsome little museum.

Home with Gothic windows featured in a famous painting.

A four story, football field-sized, nine-grotto creation made of shells, minerals, and rare stones.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

A terrific purveyor of natural history objects and curios.

Over thousands of years, this slot canyon was carved out of the bed of an ancient lake.

A unique botanical garden housed in three giant geodesic domes.

Restaurant in Northern Wisconsin comes with a unique feature: a grassy roof covered in living goats.

Vikings and Evangelicals have both had a hand in this replica medieval church.

To find the "unicorns of the deep" you've got to go downstairs.

Years of archaeology, just chillin' by the water cooler.

These pretty kitties killed and ate as many as 135 railway workers.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

An outdoor urban gallery of large-scale artworks by the world's most influential street artists.

This steep-walled ravine contains animal-shaped formations made from sandstone.

"World's largest scrap metal sculpture" stands in an outdoor sculpture garden in the middle of Wisconsin.