Due to its rocky shoreline, this beach is geared for older kids and snorkelers. Its nickname refers to the distance between the park and the downtown post office. For swimming and snorkeling, head to the eastern side, which has a deep, protected basin with generally calm, clear water and pockets of white sand. The park's western side is open ocean and much rougher, attracting local surfers when waves pick up. There are restrooms, showers and picnic areas, but no lifeguards.