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

A self-built castle made by a mysterious man.

Ancient pueblos built into the base of a natural canyon wall.

An artificial crater field that trained astronauts for lunar exploration.

Water of undetermined depth has attracted rare fish and cult leaders alike.

Ten 25-foot-tall, beehive-shaped kilns, abandoned in Death Valley.

One of the most unusual geological features, recognizable from a dozen hit movies.

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

An abandoned Jazz Age dream home and con man's hideout in Death Valley.

Smooth basaltic rocks tell a tale of ancient glacial waterfalls.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."