One of the oldest reform schools in the United States, home to wayward boys such as Merle Haggard, now abandoned.

Tenacious mummies survived dental problems, eternal entombment, and more than their fair share of devastating fires.

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

An artsy hidden staircase leads to breathtaking views of San Francisco.

The oldest Naval cemetery on the West Coast.

The former Naval shipyard is open for exploring - mostly.

The haunting ruins of Jack London's dream house.

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.

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

Social saloon from a scrapped trans-Pacific 19th century steamer.

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.