With its calm waters, lifeguards on every corner of the beach, and depths that don't exceed nine feet, it's pretty safe to say this manmade atoll pool, open daily till six or seven, is the only playa in town where kids can frolic in the sand unattended. Tidal action from bordering Biscayne Bay flushes the pool's warm waters naturally, keeping them clean and bacteria-free (assuming the bay happens to be, too). Meanwhile parents who've paid the four-dollar-per-car entry fee might as well stick around and enjoy some time to themselves, roaming the park's nature trails or grabbing a bite at Matheson Hammock's Red Fish Grill. There also are a snack bar and picnic pavilions nearby, so you can stay within earshot should Junior need you. But before dropping off your offspring, make sure they're well equipped with sunblock, that they know how to swim (duh!), and that they're all beyond six years old. Although the park doesn't prohibit unsupervised older kids, for the record, they don't recommend it either. As one employee cautions, "This is Miami, after all."