It's big, it's a ball, and it's made of twine—the world's largest of its kind.

A faithful reproduction of Al-Jazari's enormous water clock.

Whitewashed mosque contains the world's largest carpet.

Museum preserving torture methods from the past.

The graffiti-covered remnants of a former triangulation station are balanced precariously on this California peak.

Impossibly life-like natural history models created out of glass by a father and son.

Less a museum than a bizarre fantasy world created by artists and engineers.

Bouncing, delightful, mechanical art at the MIT Museum.

Faceless white figures loom over the city from the rooftop.

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

A library built during San Francisco's pioneer times is a student's retreat, bibliophile's sanctuary, and chess player's delight.

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

Its buzzing collection honors vibrator history.

Nestled in the heart of San Francisco’s bustling Financial District stands a unique homage to the Mayan and Beaux Arts.

Early prototype for Frank Lloyd Wright's Guggenheim.

Half of a house.

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

Only hotel where you can legally launder money.

A still functioning vaudeville carousel that has operated for over a century boasts a colorful menagerie and past.

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

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

A mysterious painting of the self-declared Emperor of the United States watches over a local hof-brau.

Furniture tries to escape an abandoned building in San Francisco.

The miraculous hydrant that saved the Mission District in 1906.