Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

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

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

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

A winding path built in secret on the edge of the continent.

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

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.

A huge musical instrument played by the ocean.

Fake subway tiles were installed to cover a design that resembled the Confederate flag—it's unclear if the resemblance was intentional.

An office built to look like a giant basket.