Miami Beach's beaches are the reason most visitors come. The main beach runs almost the entire length of the island — 10 miles of Atlantic-facing sand, broad and mostly well-maintained, with lifeguards on duty daily. The sand is white and the water is warm; the colour is genuinely the deep aqua-blue of the postcards.
South Beach proper (roughly 1st to 15th Street) is the busiest and most famous section. Lummus Park provides tree cover and volleyball courts. The water near the jetties at Government Cut (the southern tip) is calm and good for swimming. Further north, from 20th Street upward, the beach becomes progressively quieter; by 53rd Street and North Beach you can walk for long stretches without crowds. Haulover Beach, at the northern end, has a clothing-optional section that is popular and established.
The gulf-side waters on the bay side of the island are calm but less appealing for swimming — the beaches there are narrower and face the shipping channel.