Early prototype for Frank Lloyd Wright's Guggenheim.

The oldest dim sum restaurant in the United States is a nostalgic jewel.

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

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

Faceless white figures loom over the city from the rooftop.

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

This tall and trim architectural oddity is one of the skinniest buildings in San Francisco.

The oldest alley in San Francisco is paved with a reminder of the city's original shoreline.

A porcelain company's former dumping ground, completely covered in pieces of collectible ceramics.

A crumbling Beaux Arts monument to the Bay Area's age of rail.

An abandoned 1920s-era stretch of cabins now overshadowed by the 66 Motel.