A collection of 20th-century automata, penny arcade games, and musical contraptions.

The haunting ruins of Jack London's dream house.

The largest drain hole in the world.

This former boomtown "island" is now submerged below Folsom Lake.

A man-made island in scenic San Francisco Bay.

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

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

Forgotten and then destroyed by fire, this was once one of the largest saltwater swimming pools in the world.

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

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

Carnivorous plants, medieval aphrodisiacs, and the largest original wood structure glass conservatory in the western hemisphere.

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

Golden Gate Park's historic collection of plants.

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

Olfactory delights in San Francisco's Botanical Gardens.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

Concrete strongholds stand guard over the Golden Gate.

Bits and pieces from the ill-fated Donner Party's winter cabins.

Nursery with extensive collection of flesh-eating plants operated by the author of "The Savage Garden."

A trash dump made beautiful by nature's power.

The Empire Mine is "one of the oldest, largest, deepest, longest and richest gold mines in California."

The former Naval shipyard is open for exploring - mostly.

The oldest Naval cemetery on the West Coast.

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