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

A world-class observatory in the California desert.

An optical illusion found amid a logged redwood forest.

Megachurch turned Catholic church comprised of 10,000 glass panes.

One of the oldest reform schools in the United States, home to wayward boys such as Merle Haggard, now abandoned.

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

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

The unbelievably opulent home built for an infamous newspaperman.

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

This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

The site of murders and Satanic cult gatherings.

An inconspicuous footbridge beloved by San Diego locals.

Abandoned bridge hidden deep in the San Gabriel Mountains.

The largest permanent Monopoly board makes one of the longest games even bigger.

This grand mansion has starred in everything from Bones to Buffy.

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

A look into the Church of Scientology's deeply unfavorable view of psychiatry.

Rainbow-hued local gem in Venice.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

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

A one-of-a-kind collection of a unique medium.

This iconic L.A. bookshop is housed in an abandoned bank—both symbolic and chic.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.