A popular tourist cave with a dark past.

One of the last free public hot springs is decorated with hippie art.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

A museum dedicated to the alleged Roswell Incident.

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

A giant chess set, minus the psychedelic drug trip.

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

A hotel and restaurant serving as the mecca of kitsch.

A chain of bells connect the California Missions and honor the legend of the "King’s Highway."

An alley covered with 20 years of bubble gum.

A massive volcanic plug is now a protected area that hosts a number of bird species.

Rising out of miles of farmland, these buttes are sometimes called the world's smallest mountain range.

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

Yo, Adrian!

Bug-devouring flora are the stars of a special wing of the glass conservatory.

Arcadia is home to a haven for nature geeks and 80s TV lovers alike.

Where the alchemists dream of transmuting base metal into gold was actually achieved.

Julia Morgan's Moorish-Gothic labyrinth of fountains, trees, natural light and Oakland's notable dead.

Oakland's beautiful monumental cemetery.

Spiral labyrinth hidden in the hills above Oakland, CA.

Thousands of crosses and markers for soldiers who lost their lives in Iraq and Afghanistan blanket a California hillside.

Cows on a ranch are commonplace, scattered cow bones everywhere? Not so much.

This mountaintop beacon is only lit three times a year but shines like some kind of all-seeing eye.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.