According to the East Bay Regional Park District, "Don Castro Regional Park is a 101-acre urban oasis on the boundary between Hayward and Castro Valley. " The park includes a lake, the San Lorenzo Creek Reservoir. "Fishing is available year round and 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."