California's own majestic geyser is powered by a subterranean volcano.

The awe-inspiring ship from the golden era of cruising has an incomparable history and a reputation as one of the world’s most haunted places.

The haunting ruins of Jack London's dream house.

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

San Francisco's oldest operating hotel, with a Victorian atmosphere and a "haunted" fourth floor.

A popular tourist cave with a dark past.

Home to the "Circus" trees created by Axel Erlandson.

The fossilized remains of ancient California redwoods.

The lighthouse central to the 1980s horror classic "The Fog" is, in fact, located in one of the foggiest areas of the Pacific Coast.

A modern day curiosity cabinet.

Since 1973, this block has been home to the most concentrated collection of murals in San Francisco.

An overlooked and unassuming engineering marvel.

The stones that traveled from Spain to eventually become a holy place for San Francisco's nature worshippers.

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

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

A Barbary Coast watering hole built into a Gold Rush shipwreck.

One of the oldest producers of hand-folded fortune cookies still uses its original secret recipe.

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

Life in this isolated, hilltop lighthouse was lonely, but it sure was lovely.

A hidden subterranean installation offers a view of the sky.

The giant pair of sexy legs sticking out the window of this costume store have become its main draw.

California's own medieval Italian castle, authentic down to the 300-year-old iron maiden in the dungeon.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

This private residence was the template for one of the most beloved television homes of all time.