One of the world's oldest and most massive living organisms is a grove of quaking aspens.

Take a drunken tour inside the world's largest known geode.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

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

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

This frequently-photographed waterfall takes only a short hike to visit.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

A hotel and restaurant serving as the mecca of kitsch.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

A stunning, two-tiered waterfall made famous by poets, artists and the legend of a ghost dog.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

An underwater city for the dead.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

A favorite haunt of dinosaur loving children and hallucinogen loving hippies alike.

This unique structure in suburban Austin is made up entirely of other people's castaways, and constantly changing.

Giant busts of 42 U.S. presidents are sitting in a field in Virginia.

Hollowed out cedar log tubs set in an ancient towering forest.

One of only two commuter aerial tramways in the United States.

A heavenly experience, right here on Terra Firma.

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

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

A beautiful geyser under environmental threat.