The United States' first transcontinental automobile road came to its end at this spot in San Francisco's Lincoln Park.

A modest reminder of treacherous waters at the Golden Gate.

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

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

A hidden gem, named after a San Franciscan icon, offers spectacular views of the Pacific Ocean.

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

A miniature view of the park, caught in time.

Depicting scenes of everyday life - and specific individuals - in Great Depression era San Francisco.

This abandoned boat was left in place thanks to its rotting beauty.

'Cause the fence start shaking, the earth was quaking.

Overlooking the Colorado Convention Center is this giant sculpture made from thousands of triangles.

This sidewalk tribute honors Colorado's great culinary creation.

This 19th-century church is now a popular roller rink.

A garden oasis filled with flowers mentioned in the works of William Shakespeare.

Barely visible foundations remain where Stow Lake’s “observatory” once welcomed visitors.

A hidden subterranean installation offers a view of the sky.

A masterpiece in Golden Gate Park by virtue of the artist’s debt.

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

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

San Francisco's first World's Fair, dedicated to the wonders of California.

The legendary statue-hating superintendent of Golden Gate Park is honored with... a statue.

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

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

A famous alternative culture epicenter and where Joplin serenaded young hippies.