Visible below the waves are memorials to the city's Gold Rush dead.

An essential stop before plundering, BYO Cutlass.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

A nondescript building that's been functioning as a speakeasy for nearly a century and a half.

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

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

Tiki luxury on Nob Hill.

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

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

San Francisco's newly reopened hands-on science museum.

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

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.

Its buzzing collection honors vibrator history.

Towering basalt columns, a creation of fire and ice.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

The rocks in this arid basin leave trails of movement behind them.

The ghostly remains of an accidental sea.

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

High on a hill overlooking Los Angeles lives a world famous, high-power conical Tesla Coil.

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

Built for television, this statue now serves as an unlikely memorial to a fireman who died on 9/11.

When the town wouldn't allow the fast-food behemoth to build a new restaurant, they put one inside an 1850 home.