The Farasan Islands are more than 170 coral reefs lifted above the Red Sea off southwestern Saudi Arabia, and what lifted them is salt. A buried dome of it, left when an old sea evaporated, is still rising and pushing the dead coral up with it. The reef flats run so shallow that you wade a long way from shore with the seabed glowing under you, and then the coral rim falls away into clear water thick with fish. Some of the Red Sea's densest mangrove stands line the inner channels, roots gripping the tideline in water the colour of weak tea, herons in the shallows and ospreys at the channel mouths. Only the main crossing has a bridge and a timetable. To reach the uninhabited outer islands you strike a deal at the harbour with a captain and his fishing boat.
Farasan town's old core is cut out of the reef itself, coral sawn into blocks. The pearl money that paid for it is still on those walls: the Al-Najdi mosque and the Al-Rifai house wear gypsum carved into lace, coloured glass throwing patches across painted ceilings. That money vanished within a decade. The island's crews worked the pearl banks each summer, until Japan learned to culture pearls and the natural market collapsed in the 1930s. A Latin inscription found here in 2003 records Roman soldiers stationed on this coral island, a thousand kilometres further south than anyone thought Rome's army had reached. Around a thousand gazelles live on the main island, a subspecies of their own, and you see them on the road verges at first light. They do the place one disservice: they eat the sugary pods of mesquite, the worst invasive tree here, and plant its seed as they walk. Once a year the sea delivers what the islands are known for. For a few nights around the full moon in April, parrotfish gather in the shallows to spawn. The islanders know it is on from a scent that comes ashore after sunset, and the whole town wades out with nets.