The first AIDS memorial chapel in San Francisco and one of only a few in the U.S.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

A favorite haunt of dinosaur loving children and hallucinogen loving hippies alike.

Its buzzing collection honors vibrator history.

A winding path built in secret on the edge of the continent.

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A psychedelic labyrinth on the San Francisco bay.

A huge musical instrument played by the ocean.

A pair of pure white felines guard the entrance to a spot of California real estate established as an artist's haven.

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

This quirky roadside attraction dives into the many theories surrounding North America's most infamous hairy cryptid.

An abandoned boat that's been stranded mysteriously for decades.

It should come as no surprise that the world's largest artichoke lies in the town that calls itself the "Artichoke Center of the World."

During World War II this was the site of an "honor camp" used as a prison for draft dodgers, Native American conscientious objectors, and Japanese-Americans—including a man who brought his case against the camp to the Supreme Court.

The fading, forgotten remains of a once bright and booming factory.

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