These four islands right offshore have waterfalls, colorful lights, fancy buildings, and a secret purpose.

The blinking light atop the iconic landmark has been sending secret messages for decades.

This dormant volcanic crater has been converted from a roiling pit of magma to a pleasant hiking spot.

The most isolated mailbox in America lets desert travelers record their passing.

The show's fictional Korean medical camp was created in the Santa Monica hills.

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

L. Frank Baum wrote part of the "Wizard of Oz" series in this wooden Victorian beach resort.

A music-filled, booze-soaked oasis in the desert.

Semi-recognized center of the world, with many oddities.

Happy harbor seals frolic and snooze on this warm, sandy stretch of coast.

The awe-inspiring ship from the golden era of cruising has an incomparable history and a reputation as one of the world’s most haunted places.

The abandoned train depot now doubles as a well-placed rest stop for those who take the road less traveled.

A pair of large white marble lions guard this stretch of the Mojave Desert, and it is utterly mysterious how they got there.

A world-class observatory in the California desert.

A fake town founded by Western movie stars is now becoming a hip desert community.

A sign at the end of the Santa Monica Pier marks the traditional end of the legendary American highway.

Once strictly off-limits, this lower level housing curious and priceless vehicles of the Petersen Automotive Museum is now open to the public.

A former utopian healing center created by a huckster and built by derelicts.

The highest dunes in California are the most likely place in the area to hear the Singing Sands.

A volcanic tunnel illuminated by natural skylights offers a shaded respite from the desert sun.

A desert ghost town—occupied for only 12 years—was once home to more than 500 silver mines.

One of the ghostly stops along Route 66.

San Diego's most historic and haunted home.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.