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

A favorite haunt of dinosaur loving children and hallucinogen loving hippies alike.

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

A pier that used to act as a busy ferry dock is now a decaying favorite of local fisherman and urban artists.

A playground built by the kids that is a child's wonderland, and a helicopter parent's nightmare.

A 90-acre park on former landfill that hosts an annual kite festival.

This partially buried wreck is one of the most complete of its kind but is only revealed when the sea allows.

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

An amazing collection of fantastic reptiles, amphibians, spiders, and insects.

An vast warehouse of everyday treasures in Berkeley, CA.

A crumbling Beaux Arts monument to the Bay Area's age of rail.

A ruined hotel with an unlucky history and an eerie present.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.