The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

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

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

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

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

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

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

At the base of the Golden Gate Bridge, a small sign basically begs for a high-five.

Once the gateway to the utopian dream-village of a Civil War embalmer.

One of the last remaining Carpenter Gothic churches is situated on a wildflower conservatory overlooking the bay.

Internationally-recognized arts center housed in a century-old former military barracks.

An abandoned, unfinished mansion on grounds strewn with lava rocks.

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

Concrete strongholds stand guard over the Golden Gate.

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.

A living time capsule of the 1960s Richardson Bay water-front.