Before it was abandoned and left to rust alongside the road, this riverboat starred in a John Wayne movie.

A modest reminder of treacherous waters at the Golden Gate.

One of the oldest producers of hand-folded fortune cookies still uses its original secret recipe.

An abandoned, unfinished mansion on grounds strewn with lava rocks.

The largest dune field in the Mojave offers a chance of hearing the 'singing sands.'

Another of California's unused Cold War missile defense complexes has become a graffiti gallery.

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

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

A ruined hotel with an unlucky history and an eerie present.

The liveliest ghost town in the state.

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

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

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

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

San Francisco Bay's ghost town.

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

This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

The "Fun Spot of the Desert" is now a haunting ruin, and a reminder that putting a water park in a desert is a bad idea.

The remains of a ruined mansion memorialize the 1906 earthquake.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

Abandoned bridge hidden deep in the San Gabriel Mountains.

This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

An unfortunate geological resemblance to Satan has labeled this Pasadena gorge as a passage to the underworld.

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