Costumed elves and mountain bikers co-exist peacefully at this abandoned Christmas-themed adventure park.

Abandoned bridge hidden deep in the San Gabriel Mountains.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

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

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

The ghost town that ended up on Ebay.

A Swedenborgian glass church surrounded by redwoods sits perched atop a massive landslide area.

Historic funicular railway, believed to be the shortest railroad in the world.

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

This serene oasis in an affluent Los Angeles neighborhood holds some of Gandhi's ashes and got Elvis into Eastern Philosophy.

Canyon walls shrouded in ferns.

Explore 10 acres of environmental sculptures.

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

Tiki luxury on Nob Hill.

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

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

Rainbow-hued local gem in Venice.

Left untouched since a double murder-suicide in the 1960s, Los Feliz murder mansion remains a neighborhood mystery.

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

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

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

Hidden in the hills of Hollywood, this secluded Oz-themed garden is dotted with dozens of thrones.

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

Giant Redwood-themed cafeteria operates under the golden rule, "Dine Free Unless Delighted."