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

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

See massive fossils that are over 200 million years old in northeastern Arizona.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

Historic funicular railway, believed to be the shortest railroad in the world.

Less a museum than a bizarre fantasy world created by artists and engineers.

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

Canyon walls shrouded in ferns.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

A museum dedicated to the alleged Roswell Incident.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

Its buzzing collection honors vibrator history.

Paranormal experiences in this hotel's room 217 led Stephen King to write "The Shining."

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

A trash dump made beautiful by nature's power.

A bizarre house filled with an astounding array of collections.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

The legendary building that needed ghostly approval before being built.

Funded by John D. Rockefeller, this is one of the earliest, and most beautiful, shopping arcades in America.

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

This lovely university observatory continues to sit abandoned since its potential savior was sent to jail for fraud.