A promotional sun clock on the site of San Francisco's great raceway.

Visible below the waves are memorials to the city's Gold Rush dead.

A life-sized mammoth sculpture marks the spot where the remains of a Columbian mammoth were discovered in 2005.

A lonely monument to the original Silicon Valley tech campus.

Three plaques mark the spot where the "forgotten father of broadcasting" worked.

A mysterious monument covered in a binary code marks the heart of tech.

For roadside fast food, pull over at the giant orange.

It is locally loved and ridiculed for literally looking like poop.

The smallest country in the world.

One woman's Viking Castle on Lake Tahoe.

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

Bits and pieces from the ill-fated Donner Party's winter cabins.

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

A breathtaking 19th-century trail overlooks Lake Tahoe.

Historic home to one of the most famous women pioneers of the 19th century.

Eastern zen meets Western grit in these four little trees growing out of a rock on Lake Tahoe’s Nevada shore.

A fiery crater has been burning in the Karakum Desert since 1971.

This historic aviation building is now a museum owned and operated by Disney.

L.A.'s oldest operating bowling alley is a beautifully restored homage to its speakeasy days.

An extraordinary final resting place full of oversized art, amazing statues, and dead celebrities.

The legendary building that needed ghostly approval before being built.

A common entry point to the Griffith Observatory trail holds its own wonders.

The first all glass and steel residence in the United States.

This weird abode has inspired everything from the "House On Haunted Hil" to a robot hunter's pad.