A popular tourist cave with a dark past.

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

A huge collection of rocks, gems, and crystals.

Puzzling...this tree looks like an assemblage of dismembered monkey limbs.

The California capital city once stood 10 feet lower than it does today.

I Street Bridge is the heaviest swinging center bridge in the United States.

California's oldest existing theater building hosted an impressive cast of celebrities, including hosting Mark Twain's first lecture.

The Empire Mine is "one of the oldest, largest, deepest, longest and richest gold mines in California."

This 19th century hydroelectric powerhouse was the first of its kind.

This former boomtown "island" is now submerged below Folsom Lake.

Eclectic collection of dark and macabre antiques.

Dentist's hated concrete colossi are now beloved icons of the community.