Start with the correction, because almost every guide gets it wrong. The lifeguard towers of Miami Beach are not numbered one to thirty-six. There is no tower six in the sense of a sequence. Each one is known by the cross street it stands at — the 10th Street tower, the 14th Street tower, the 21st Street tower — and that is how Ocean Rescue dispatches to them, how locals arrange to meet at them, and how you should think about them. Working south to north through South Beach, there are stations at the jetty and South Pointe, then at 1st, 3rd, 5th, 6th, 8th, 10th, 12th, 13th, 14th, 15th, Lincoln Road, 17th, 18th and 21st Streets, with the line continuing north through Mid-Beach to the mid-80s streets.
They exist in their current form because of a hurricane. Andrew crossed south Miami-Dade in August 1992 and destroyed a number of the city's stands. The City of Miami Beach commissioned the architect William Lane to design replacements, and in the years that followed he produced a set of towers that borrowed openly from the buildings across the sand: deco eyebrows and stepped parapets, mid-century angles, portholes, finials, and colour schemes drawn from Caribbean paint rather than beach beige. Roughly two decades later the city asked him back to design a second generation — reported as six prototypes — to replace the ageing fleet of around three dozen towers.
No two adjacent towers are alike. That was deliberate, and it is what turned a piece of municipal safety equipment into the island's most reproduced image. They appear on more postcards, phone cases and rental-car adverts than any building on Ocean Drive.
They are also, and primarily, working stations. Miami Beach Ocean Rescue staffs them through daylight hours, and the coloured flags flying from them are the day's verdict on the water. That combination — genuinely useful public infrastructure that also happens to be good design, commissioned by a city government after a disaster — is the most Miami Beach thing on this list.