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

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

Olfactory delights in San Francisco's Botanical Gardens.

A museum befitting the city responsible for supplying the majority of the world's LSD.

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

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

This shop specializes in oddities and Victorian-inspired wonders.

A 140-year-old castle with underground caves hidden in San Francisco.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

A psychedelic labyrinth on the San Francisco bay.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A huge musical instrument played by the ocean.