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

Its buzzing collection honors vibrator history.

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.

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.

The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.