This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

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

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

A 300-ship graveyard, with a few still visible at low tide.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

Visible below the waves are memorials to the city's Gold Rush dead.

Eons old volcanic activity created one of the most stunning rock formations in the United States.

A modern mechanical planetary system, part of a 10,000 year clock.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

A ghost town at the airport is now a refuge for blue butterflies.

An inconspicuous footbridge beloved by San Diego locals.

Carved by a waterfall in a hard-to-reach rock formation, this heart-shaped rock has inspired romantics for decades.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

A shop full of natural curiosities, carnivorous plants, and costumed taxidermied mice.

A meditative space out of a fantasy story.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

San Francisco's newly reopened hands-on science museum.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

The ghostly remains of an accidental sea.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.