The scale of Fleishhacker Pool defied easy comprehension. At 1,000 feet, it was longer than three football fields laid end to end. The saltwater was pumped from the Pacific Ocean and heated, a engineering feat that required constant maintenance and enormous energy costs. The pool was part of a larger complex that included the Fleishhacker Playfield, and together they offered the residents of San Francisco's Outer Sunset and Parkside neighborhoods -- and the entire city -- a recreational facility of almost absurd generosity. Lifeguards used rowboats because the pool was too large to supervise from the edges. On busy summer days, the water surface was a mosaic of thousands of swimmers.

The pool's origins were tangled with San Francisco's water infrastructure. In 1921, the Spring Valley Water Company finalized its project to bring Yosemite spring water to San Francisco via the Hetch Hetchy system, and donated the pool's land to the city as part of this massive infrastructure project. Fleishhacker seized the opportunity, funding the pool and playfield as civic gifts. The gesture was characteristic of an era when wealthy San Franciscans competed to endow public amenities -- parks, museums, monuments -- that would bear their names and serve the public simultaneously. The pool was free for decades, a democratic space where the city's working families could swim alongside anyone else.

Maintaining a pool the size of a small lake proved unsustainable. The costs of heating millions of gallons of seawater, the constant battle against saltwater corrosion, and the declining popularity of public pools in the age of backyard swimming conspired to doom Fleishhacker Pool. It closed in 1971 after forty-six years of operation. The empty basin sat for nearly three decades, filling with rainwater and memories, before being demolished in 2000. Today the site is part of the San Francisco Zoo's grounds. Nothing remains of the pool except photographs, civic records, and the stories of San Franciscans who remember swimming in something that felt less like a pool and more like an ocean with walls.