Ten entries strung along a single road, which makes the Keys the easiest region in the register to plan and the slowest to actually drive. US-1 runs the length of it and there is no alternative route, so allow considerably more time than the mileage suggests.
The concentration is remarkable for a chain of islands with so few people on it. A doll who receives apology letters. A tower built to house bats that flew away and never came back, and that Hurricane Irma flattened in 2017, leaving the marker. A bronze figure standing out on the reef, close enough to the surface that snorkellers reach it on a calm day. A hotel on the floor of a lagoon that you have to dive to check into.
At the far end, seventy miles past Key West and reachable only by ferry or seaplane, is the largest brick structure in the Americas, unfinished, on an island with no fresh water. That one is a whole day on its own.
