Sombrero Beach

There is very little sand in the Florida Keys, and the reason is that almost none of it arrives from anywhere else. Mainland Florida's beaches are quartz, carried down by rivers draining the southern Appalachians, and none of that sediment reaches this far out to sea. What the Keys have instead is carbonate, manufactured on the spot by coral, molluscs and the parrotfish that grind them down, and it is fine enough to settle as marl and mangrove flat rather than pile up into a strand. The reef offshore absorbs most of the wave energy that might otherwise build one anyway. So a proper sand beach here is a local exception, and Sombrero Beach, on the south shore of Key Vaca at the end of its own road, is the best of the handful in Marathon. The City of Marathon rebuilt the park in 2001 to be accessible throughout, with a paved path down from the road and shaded pavilions along the back of the sand. From April through October loggerhead turtles come ashore here after dark to nest, and the beach is managed around them. Four and a half miles offshore stands the Sombrero Key Light, lit in 1858 and the tallest of Florida's reef lights, an iron skeleton tower planted on the same reef that keeps this coastline from making much sand of its own.