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

Hollywood's most famous landmark, the "temporary" sign that has stood for decades longer than intended.

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

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

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

A hand-built folk art installation covered with messages of God's love.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

America's most famous piece of self-built architecture.

The abandoned zoo enclosures offer a perfect place to experience the other side of the bars.

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

A psychedelic labyrinth on the San Francisco bay.

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

Barely visible foundations remain where Stow Lake’s “observatory” once welcomed visitors.

This former stomping grounds of the most eminent astronomers of the early 20th century.

A nursery specializing in strange and beautiful succulents and cacti.

This beautiful ridge-top trail is dotted by tiny homes apparently built by a group of itinerant fairies.

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

Abandoned bridge hidden deep in the San Gabriel Mountains.

The most unique castle in all of Southern California, entirely constructed from repurposed materials.

The site of murders and Satanic cult gatherings.

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

A living museum dedicated to the legendary woodworker and his soulful furniture.

Mexican food and folk art.

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