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

This massive crater in the middle of nowhere was used to train astronauts for moon landings.

The farthest you can be in the contiguous U.S. from a McDonald's location.

Smooth basaltic rocks tell a tale of ancient glacial waterfalls.

The world’s largest concentrated solar plant generates as many problems as megawatts.

Where NASA's satellites and rovers phone home.

One of the world's largest telescopes, stares into the night sky with two huge mirrors.

A preserve with 75,000 ancient drawings remains the realm of public – not just scientific – exploration.

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

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

A decommissioned Naval base now rents itself out for people who want to blow stuff up.

Legends surround this jagged rock formation in the New Mexico desert.

These aggressively sustainable art homes look like something out of 1970's science fiction.

This volcano rises like a giant anthill from the plains below, with a road spiraling up to the rim.

The secret city built by the Manhattan Project.