This subtle Berkeley paving stone actually marks off a lawless tube of air that extends into space.

A shape-shifting buy-sell-trade bookstore, born to Beatnik Era spirit.

The century-old bell and clock tower at UC Berkeley is the third-tallest in the world, and has fossils.

The rusting remains of the largest assembled WWII fleet on the West Coast.

A sparse, solitary sequoia still stands as a living tribute to the famous conservationist who planted it—but it's dying.

The perfect spot for a picnic, right next to a giant ballistic missile.

The oldest Naval cemetery on the West Coast.

The former Naval shipyard is open for exploring - mostly.

The unedited photograph called "Bliss" has graced the screens of over a billion computers.

The fossilized remains of ancient California redwoods.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

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

An unassuming grey box sitting on San Francisco's Pier 17 is a "sky diary" of the coastal city's temperamental weather.

Once the fastest ship from San Francisco to Tahiti, the Galilee now lays in pieces in three different cities.

Built in 1906, this unique building was the first Hindu temple in the United States.

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

The neighborhood church casts a breast-shaped shadow that locals have come to call the “two o’clock titty.”

Chevron maintains one “Standard” brand station per state so it doesn’t lose the trademark.

This one-block alleyway is stuffed with street art that is colorful, cultural, and intensely political.

The miraculous hydrant that saved the Mission District in 1906.

This surreptitious shop is only open five hours per week.

These subterranean storage areas hold emergency water reserves.