Eons ago, a rushing lava river formed this pristine passage through solid rock.

See massive fossils that are over 200 million years old in northeastern Arizona.

A reproduction of earth's many biomes.

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

Dramatic river bend surrounds a natural red-rocked pedestal.

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

Rippling sand dunes frozen in the Arizona rock.

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

The "world's biggest dinosaur" once housed a creationist museum in its abdomen.

This California tree is the single source of the state's entire orange industry.

The Route 66 institution that inspired Taco Bell also served as an important headquarters for Mexican-American social movements.

The lighthouse central to the 1980s horror classic "The Fog" is, in fact, located in one of the foggiest areas of the Pacific Coast.

A natural dome made of volcanic glass in Inyo National Forest.

Towering basalt columns, a creation of fire and ice.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

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

These unique stepping stones hug a river's edge to take hikers on a journey through a limestone gorge.

Quite simply the largest tree in the world (by volume).

A 19th-century cabin built into a hollowed-out Sequoia tree.

The location of the last stand of Charles Manson's doomsday cult.

Each year these high desert hills are absolutely covered with poppy flowers in a surreal show of nature.

Finale of "William Tell Overture" can be heard as drivers pass over grooves in the road.

Named after a bandit and the star of several Hollywood prehistoric landscapes, these sandstone formations are a historical part of the Los Angeles natural landscape.