The Don Castro lagoon and adjacent lake were created in 1964 when the Alameda Flood Control and Water Conservation District dammed San Lorenzo Creek. Today the lagoon is supplied with water from EBMUD. A large shallow area is roped off for children. The adjacent lake is closed to boating and swimming, but hikers along the shore will discover a surprising wilderness in miniature, where turtles and frogs splash in the water, ducks rest in the reeds and raccoons and deer come down to drink at sunset. Anglers along the lake may catch trout, bass, catfish and bluegill. The lake is stocked regularly with trout and catfish.