(The San Francisco Association of Realtors draws a wider southwestern boundary and calls the adjacent neighborhood Sunnyside.)[5] The Glen Park neighborhood consists of residential, commercial, and "public" city planning zones, specifically the following zones:[6][7][8] To the west, upper Islais Creek, historically the largest creek in San Francisco, still flows above ground through Glen Canyon from the southern slopes of Twin Peaks.The first named streets in Glen Park were mapped in 1872 on land that had been occupied by milch rancher (i.e., dairy farmer) George Ulshofer as early as 1859 or 1860.[13] Opening in 1898, it attracted 8,000 to 15,000 people each weekend for its vaudeville shows, daring aeronautic displays, sporting events, and animal exhibits.[15] Public spaces include Walter Haas Playground, Billy Goat Hill Park, and Fairmount Plaza.