The world's first hotel built in an abandoned water-filled quarry.

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

Rather than a run-of-the-mill franchise hotel, this lodging has been decked out in dinosaur decor.

This impressive tunnel was dug entirely by hand over the course of 36 years.

The remains of a ruined mansion memorialize the 1906 earthquake.

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

Furniture tries to escape an abandoned building in San Francisco.

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

Canyon walls shrouded in ferns.

An eccentric folk art landmark made out of discarded bottles by an inspired "grandma."

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

Acres of natural wonders left behind by a socialite-turned-gardener.

Abandoned anti-ballistic missile base.

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

The hidden jewel of Disneyland: a members only playground for the Disney elite.

Remains of a Greek freighter trapped off of Rocky Point in 1961.

From pre-war whiskey cocktails to prohibition-era speakeasy secrecy, this bar has seen it all.

The private clubhouse for the members of the Academy of Magical Arts.

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