The key to turning shifting dunes into the green oasis of Golden Gate Park.

Depicting scenes of everyday life - and specific individuals - in Great Depression era San Francisco.

A miniature view of the park, caught in time.

Once the largest windmill outside of Holland, with enormous 114 foot sails.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

A walk-in working camera obscura produces 360-degree live images of the San Francisco coast.

A man-made island in scenic San Francisco Bay.

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

A 300-ship graveyard, with a few still visible at low tide.

A winding path built in secret on the edge of the continent.

San Francisco's urban bison herd has persisted in the face of extinction, development, and disease.

Shoot for par over the bodies of the dead on this cemetery-cum-golf course.

Guns that have been defending San Francisco since 1904.

The remains of a ruined mansion memorialize the 1906 earthquake.

Inside an old airplane hangar, friends and strangers alike play on a massive trampoline.

Prone to disastrous fires, the city of San Francisco has the Guardian, a fireboat gifted by residents, to watch over them from the bay.

San Francisco's newly reopened hands-on science museum.

Floating man-made island and upscale restaurant.

A hidden subterranean installation offers a view of the sky.

The remains of a 12th-century chapter house in Golden Gate Park.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

Golden Gate Park's historic collection of plants.

Art in the form of a winding, man made crack in stone.

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