A multi-storied adobe complex has been inhabited for more than a thousand years.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

A museum dedicated to the alleged Roswell Incident.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

An artsy hidden staircase leads to breathtaking views of San Francisco.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

The beauty and the beast of hydraulic mining is on full display at this California Historic State Park.

A middle school sports field that many believe was the true location of the first successful powered flight - and not by the Wright Brothers.

The oldest continuously operating Catholic school west of the Mississippi.

An abandoned lot littered with concrete debris was once the home of the world's first female railroad president.

A fine mixture of the old and the new topped with an art deco neon spire.

Established in 1853, this crumbling cemetery sits forgotten on the corner of Church and Chapel in Gold Country.

Built in 1895, this bed and breakfast was once a hospital that served an early 1900s Gold Rush boomtown.

The modest home of the very immodest dancer who cost a king his crown.

When life gave this firefighter a forest fire, he made a rough-hewn sculpture park using a chainsaw.

An abandoned amusement park based on the popular 1940s Red Ryder comic strip.

A burnt-out motel with priceless Native American artwork in the basement, redeveloped into apartments.

This pseudo-steampunk weapons facility is the world's largest wood and glue structure, and packs quite a wallop.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

It should come as no surprise that the best view of the Hollywood sign is from Batman's lair.

This glamorous old building is said to have inspired the Tower of Terror.

Hidden in the hills of Hollywood, this secluded Oz-themed garden is dotted with dozens of thrones.

From silent movie theater to rock &roll palace and beyond.

Political debates in a fabulous Pasadena castle.