Fleishhacker Pool sat right next to the San Francisco Zoo. Opened in 1925, it was one of the largest outdoor swimming pools on the planet — filled with ocean water and big enough to fit thousands of swimmers. Fleishhacker Pool — The Forgotten Ocean Giant of San Francisco 🌊 An Ambitious Dream (Opened 1925) Fleishhacker Pool opened on April 22, 1925, at the edge of Ocean Beach, right next to today’s San Francisco Zoo. It was the brainchild of Herbert Fleishhacker, a wealthy banker and Park Commis