A giant donut stands as a popular symbol of Los Angeles iconography.

The sun acts as a key that only fits this giant keyhole twice a year.

Don't bother sending any mail to this ghost town.

A bigger-than-life pun that has become a beacon of altruism.

The first fresco Diego Rivera painted in the United States can be found in the former San Francisco Stock Exchange.

This print shop boasts one of the largest pinball arcades in San Francisco.

This Alamo Square mansion is rumored to have hosted satanic rituals and other occult practices.

This 19th-century church is now a popular roller rink.

One of few lasting examples of the brief octagon craze that developed into folly.

A classic advertising icon immortalized in regal bronze.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

A psychedelic labyrinth on the San Francisco bay.

This teeny-tiny park built by a San Francisco man in 1962 is mostly stairs.

A speck of nature and art in one of San Francisco’s most notorious neighborhoods.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

The first lookout in Yosemite.

A little-known, but surprisingly large waterfall on the Little Truckee River in the northern Sierra Nevada.

The disdain for this dysfunctional dam is reflected in a giant pair of scissors painted on the concrete face.

A classically inspired temple in Redwood City.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

This historic roadhouse has many tales to tell of San Francisco's early history.

The long, arduous journey of the stones of the Abbey of New Clairvaux.

Each winter this underground cave forms a dazzling ice palace.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.