The only retired U.S. nuclear missile silo that is open to the public.

This mangled and twisted wreckage left by the side of a Mexican road was no accident, but a planned crash in the name of science and safety.

The ghostly remains of an accidental sea.

Hundreds of drawings left by the land's previous inhabitants remain mysterious.

This impressive tunnel was dug entirely by hand over the course of 36 years.

In one of the hottest parts of the Mojave Desert, shallow bedrock forces the typically dry Mojave River to the surface in this canyon, providing a vital oasis for humans and wildlife.

Finally the worlds of UFO enthusiasts and beef jerky lovers have come together in this roadside shop.

A volcanic tunnel illuminated by natural skylights offers a shaded respite from the desert sun.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

The only subway station in the city that still makes use of gap fillers.

The "Seinfeld" diner.

Designed by famed 20th-century architect Cass Gilbert, the future of this abandoned 1908 rail station is currently in limbo.

Seriously good slices of Sicilian pizza lurk at the back of the Bronx's oldest enclosed market.

A basement pool hall is the front for some of the best Dominican food in New York City.

A crumbling staircase in upper Manhattan is all that remains of one of the most important sites in sports history.

A large boulder marks the place where the island of Manhattan was purportedly "sold" to the Dutch.

One of the world’s largest collections of petroglyphs records 2,000 years of human activity.

A small oasis not far from downtown Moab.

This ghost town was once a cult-like religious utopian settlement.

Only a few signs remain of the buried Colorado mining town that supplied the uranium for the first atomic bomb.

Its history includes dinosaur fossils, cattle rustlers, Georgia O'Keeffe, and a mythical giant rattlesnake named Vivaron.

At one time this small mining village was the highest town in America but now it sits abandoned while the mine churns on.

This Colorado hiking trail provides a small gold mine of abandoned gold mines.

One of the American Southwest's most extensive collections of Navajo rock art.