A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

This historic California cemetery holds the bodies of veterans of both the Civil War and the Donner Party.

340 bicycles, 65 feet high.

A sudden forest of traditional Papua New Guinean art works is hidden in a corner of Stanford University.

A comprehensive collection of Pez dispensers.

Oldest building in California still in use.

California's own majestic geyser is powered by a subterranean volcano.

An inconspicuous footbridge beloved by San Diego locals.

The miraculous hydrant that saved the Mission District in 1906.

A tribute to the life and work of the beloved "Peanuts" cartoonist.

Home to secret Eastern Bloc spy equipment and the largest stretch of the original Berlin Wall outside of Germany.

Law-protected wreckage serves as a peculiar memorial for an almost forgotten World War II tragedy.

Alleyway plaque commemorating the death of a fictional character in The Maltese Falcon, not far from the author's home.

A desert ghost town—occupied for only 12 years—was once home to more than 500 silver mines.

From pre-war whiskey cocktails to prohibition-era speakeasy secrecy, this bar has seen it all.

Gold Rush-era tombstones line the park's paths.

This Big Sur waterfall drops 80 feet directly into the Pacific Ocean, and inspired the hillside house up top.

One man's vast collection of artifacts and ephemera from matchbooks and postcards to vintage neon signs and cars.

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 oldest burial ground in the city, final resting place of city founders, Ohlone natives and murderers alike.

A Barbary Coast watering hole built into a Gold Rush shipwreck.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.

Dive bar built out of the remains of a whaling ship.

A house built from trash known as the poor man's Hearst Castle.