After Spreckels' death, Seacliff Park and Rio Del Mar Country Club (today's Seacliff State Beach) were developed in the late 1920s. Rio Del Mar Country Club included a clubhouse, a grand hotel on the bluffs, a beach club, a polo field, and a golf course. The estuary was filled in (now Rio Beach Flats) and the SS "Palo Alto" cement ship was moored and converted into an amusement pier with restaurants, swimming pool, and a dance pavilion. Both Rio Del Mar and Seacliff were popular during Prohibition as drinking and gambling were discreetly available. These amusements were interrupted by the Great Depression and World War II.