A semi-scholarly approach to sex.

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

This surreptitious shop is only open five hours per week.

This one-block alleyway is stuffed with street art that is colorful, cultural, and intensely political.

Radioactivity still cause for concern at this urban explorer's paradise.

Early prototype for Frank Lloyd Wright's Guggenheim.

Golden Gate Park's historic collection of plants.

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

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

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

A shop full of natural curiosities, carnivorous plants, and costumed taxidermied mice.

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.

Olfactory delights in San Francisco's Botanical Gardens.

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

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

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

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

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

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

A psychedelic labyrinth on the San Francisco bay.

This enormous abandoned factory is now a makeshift graffiti gallery.

Ironically this massive termite is the mascot for a company that is acclaimed for killing his kind.

An unusual library of dead things at the Rhode Island School of Design.