California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

The largest drain hole in the world.

The ghost town that ended up on Ebay.

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

The "world's biggest dinosaur" once housed a creationist museum in its abdomen.

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

The site of murders and Satanic cult gatherings.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

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.

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

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.

Experience a quartz crystal sound bath inside a storied, all-wood sound-chamber.

This massive redwood tree has a hole in the base big enough to drive through.

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

Explore 10 acres of environmental sculptures.

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

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

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

An outdoor sculpture park of giant pink robots and post-apocalyptic Christmas scenes.

Eons old volcanic activity created one of the most stunning rock formations in the United States.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

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