The only visible piece of San Francisco's most famous shipwreck.

Once the fastest ship from San Francisco to Tahiti, the Galilee now lays in pieces in three different cities.

A modern mechanical planetary system, part of a 10,000 year clock.

This odd little museum holds exhibits on everything from blacksmith equipment to hair jewelry.

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

A miniature view of the park, caught in time.

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

The sole surviving relic of the San Francisco neighborhood cobbled together from old horsecars and streetcars.

The only theatre in the world constructed specifically for sound movement.

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.

Half of a house.

A promotional sun clock on the site of San Francisco's great raceway.

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

The stones that traveled from Spain to eventually become a holy place for San Francisco's nature worshippers.

A monument to the love people have for their pets.

The restored and active Victorian-era final resting place of San Francisco.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

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.

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

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

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

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.