تحفة النظار في غرايب الامصار وعجايب الاسفار 13.81.6

13.81.6

fewer of them lie together in a ring like a circle, with an entrance like a gate through which alone ships can enter. When a ship reaches one of them, it must have a pilot from its inhabitants to guide it to the other islands. They are so close together that the tops of the palm trees on one are visible on leaving another. If a ship misses its course to them, it cannot enter them and the wind carries it to al-Maʿbar or Saylān.