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

A storybook European village in Berkeley.

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

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

This 19th-century church is now a popular roller rink.

Golden Gate Park's historic collection of plants.

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 traditional garden in the San Fernando Valley doubled for Star Fleet Academy, and is irrigated entirely by wastewater.

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.

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

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

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

The final resting place of a space program monolith.

Beautiful Victorian buildings from L.A.'s forgotten architectural past.

An extraordinarily ornate museum in San Diego holds wondrous anthropological treasures.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

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.

A "Titanic" superfan changed his name to Jack and set up this strange shrine to the blockbuster, complete with Korean food and Tarot readings.

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

Historic funicular railway, believed to be the shortest railroad in the world.

A meditative space out of a fantasy story.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.