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

This painted marvel is San Francisco's 400-foot ode to urban biking.

These subterranean storage areas hold emergency water reserves.

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

A tribute to the artist and activist who created the rainbow pride flag.

The miraculous hydrant that saved the Mission District in 1906.

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

Since 1973, this block has been home to the most concentrated collection of murals in San Francisco.

A psychedelic labyrinth on the San Francisco bay.

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

A giant statue perched on dumpsters watches over the freeway.

In 1998, Larry Page and Sergey Brin briefly ran their fledgling company from this Silicon Valley garage.

The world’s first stop-motion film was created on the racetrack outside this building.

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

Rodin's famous depiction of Dante's 'Inferno', amidst a sculpture garden of many of his other works.

Guarded by the Angel of Grief, the Stanford family tomb attracts an odd mix of halloween revelry and somber contemplation.

A hidden world of exotic succulents and cacti.

This redwood is a historic landmark, a town’s namesake, and the dancing sideline symbol of Stanford University.

A humble garage, world-famous for being the epicenter of a technology revolution.

This small monument to the great inventor contains a time capsule and a Wi-Fi hotspot.

This odd California folly seems like it was almost designed to accumulate urban legends.

The first high-tech company in the valley that actually worked with silicon devices.

A gathering of green robots at the Googleplex.

800 apricot trees honor Silicon Valley's agricultural history.