The transparent water of the Emerald cave is lit by the reflection of the sun's rays, giving it its characteristic colour. The bottom of the cave has not always been covered by the sea, as witnessed by the stalagmites rising in unusual shapes out of the water. The immersion of the cave has resulted from the slow subsidence of the earth's surface. A boat trip provides an opportunity to view this unique landscape, as well as bringing to life the many legends associated with the cave.