This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

This massive redwood tree has a hole in the base big enough to drive through.

An optical illusion found amid a logged redwood forest.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

The site of the climactic scene from the classic horror film is now a historic landmark.

The site of a classic series of Laurel and Hardy pratfalls.

Stairs often replace streets on the steep slopes of this old mining town.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

Spanning an elevation of 160 feet and containing 388 steps, this is Seattle's longest staircase.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

A curious whirlpool formation supposedly capable of entangling or engulfing branches, tree trunks, or whole rafts full of hapless tourists.

One of the largest-ever mental hospitals now sits abandoned, surrounded by 25,000 unmarked graves.

A hidden barn-sized rendition of Grant Wood's most famous, and most parodied, painting.

This spectacular public market has got meat, fish, vegetables, baked goods, and enough kielbasa for a lifetime.

One of America’s oldest and spookiest hotels, thanks to the residency of ghosts, dead presidents, and Alfred Hitchcock.

This large midwestern cavern features impressive rock formations and an underground waterfall.

The multinational Burger King chain is banned from operating within 20 miles of a family restaurant filed under the same name.

What was once the largest NFL stadium.

To honor his gardening wife, this yard artist turns bowling balls into playful, colorful sculptures.

Connecticut sites linked to the only trial to ever use demonic possession as a criminal defense.

The remains of a religious colony, its amusement park, zoo, and baseball empire.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

Perhaps the world's only gas station inspired by a political scandal.