The artist James Turrell is repurposing an extinct volcano crater as an observatory to experience the cosmos.

Witnessing the might of this dessert-colored desert waterfall is a rare, powerful treat.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

Most-visited and most-photographed slot canyon in the American Southwest.

The world's largest military aircraft cemetery.

A reproduction of earth's many biomes.

An invitation-only museum of items natural and bizarre, arcane and exotic.

At the edge of the high desert, California's second-largest natural lake is home to a unique subspecies of trout adapted to its alkaline waters.

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.

The tallest bridge in California was constructed for a project that was eventually cancelled.

The San Andreas Fault spectacularly offsets this creek.

A 250 million-year-old rock formation has earned a rather unique nickname.

Traversing these canyons, visitors can take in stunning views and glimpses of the region's history.

A remote crossroads honoring a fallen talent.

This hidden fire lookout offers spectacular views of Sequoia National Park.

Across Ring Mountain is a vast collection of Native American petroglyphs unique to the region.

A modest reminder of treacherous waters at the Golden Gate.

A massive volcanic plug is now a protected area that hosts a number of bird species.

A massive hydrovolcanic explosion left a half-mile wide crater in Death Valley.

The decaying adobe remains of an old homestead are just off the beaten path in Joshua Tree National Park.

An iconic location along the Los Angeles River where countless movie scenes are filmed.

This dormant volcanic crater has been converted from a roiling pit of magma to a pleasant hiking spot.