The tide was out, revealing greenish-blue anemones that covered the enormous black rocks jutting out of the shallows like embroidery upon a hem. We splashed into water as clear as glass, tiny waves chasing and nipping each other across the white sand. The beach was narrow, dwarfed by the towering flat plain that made up the island’s heart. Sheer cliffs of limestone rose higher than a multistoried building. Here and there, powdery dunes of pale sand piled against them like failed waves of intruders upon a city’s walls.