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

This turn of the century masterpiece has a mysterious goaty interloper.

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

Golden Gate Park's historic collection of plants.

A huge musical instrument played by the ocean.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

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

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

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

San Francisco's oldest surviving monument and meeting place for 1906 survivors.

The Empire Mine is "one of the oldest, largest, deepest, longest and richest gold mines in California."

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.