Once the most densely populated place in the world, this island is now a ghost town.

Hot springs monkey spa in the middle of Hell's Valley.

An exquisite tunnel of cascading flowers.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

A magical place that lets you play in and explore the world of Studio Ghibli.

A vibrant street away from the typical tourist track, lined with colorful, mosaic-covered houses.

This beautiful fountain was sculpted by a female artist who was ahead of her time.

This giant power line tower is a robot that can express its moods in neon.

Stenciled handprints and wall paintings dating back 10,000 years, some of the earliest forms of cave art.

A remarkable geological formation resembling a forest made of stone.

Enchanting cave with a river crashing through the roof.

This cavernous abandoned marble mine is popular with ice skaters in the winter.

Tour the world's largest deep-hole dimension granite quarry, where you can view the plant where gravestones are made and roll a ball down the outdoor granite bowling alley.

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

These tourist trap caverns are said to be the former home of a legendary Pennsylvania Hermit.

This permanent exhibition celebrates the finest of our heartless automatons both real and fictional.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

An abandoned stretch of highway, deteriorating next to the operational one.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

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

An unlikely beach paradise of giant sand dunes lies between two lakes just a few minutes from Michigan's cherry country.

This unusual three-way wooden foot bridge spans two rivers at once.