Gold Rush ship-turned-hotel buried underneath San Francisco's financial district.

Early prototype for Frank Lloyd Wright's Guggenheim.

The remains of a 12th-century chapter house in Golden Gate Park.

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

Tenacious mummies survived dental problems, eternal entombment, and more than their fair share of devastating fires.

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

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

A collection of memorabilia from the Beat era in the back of a San Francisco bookstore.

The restored and active Victorian-era final resting place of San Francisco.

A modern mechanical planetary system, part of a 10,000 year clock.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

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

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

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

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

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

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

A favorite haunt of dinosaur loving children and hallucinogen loving hippies alike.

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

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.

The only theatre in the world constructed specifically for sound movement.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.