A mesmerizing disco ball-like sculpture along the Sacramento River Walk.

Its dark depths conceal millions of rare, delicate crystal formations.

One of the oldest reform schools in the United States, home to wayward boys such as Merle Haggard, now abandoned.

Wool processing mill in an unlikely location.

Each summer, the migratory bats living beneath the bypass form "batnadoes" at dusk.

Special tunnels built so that frogs won't be killed when crossing the highway.

This historic estate on the east shore of Lake Tahoe was home to an eccentric millionaire (and his pet elephant, Mingo).

This corn maze so big you may want to pack a lunch, and possibly a flaregun.

An abandoned cyanide mill is now a haunting magnet for graffiti and illegal parties.

This hidden amusement park is a magical escape for kids and kids-at-heart.

Back in the day everyone who was anyone played this historic western theater.

A former mining hospital is now a vibrant artistic hub.

The smallest country in the world.

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

The rusting remains of the largest assembled WWII fleet on the West Coast.

The only surviving prototype of Buckminster Fuller's revolutionary car.

The oldest Naval cemetery on the West Coast.

The former Naval shipyard is open for exploring - mostly.

Location of the most powerful laser in the world, and the potential birthplace of tiny stars.

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