 The crest of the pyramid is some in extent, and is generally flat, although pitted with holes and depressions from deep, some of them filled with water.At its base there is in most places a wide belt of gently sloping land, standing not more than above sea level, and forming the brim of the hat suggesting the island’s profile.On the northern and eastern edges of the island the sea breaks against the limestone cliffs, which are deeply undercut; but elsewhere the island is circled by a broad fringing reef, which, off the western coast swings sharply away from the shore to enclose the lagoon.