The water turns from topaz to emerald inside the Grotta Verde on the south side of the Marina di Andrano. Most bathers loll about in the water at the cave entrance. The more adventurous swim through a narrow channel below an overhang into the cave. The first sight of shimmering, green light reflecting off the water, lit by the sun’s rays penetrating a large gap in the cave wall, is breathtaking. It’s hard to retreat from the jewel-like cavern – even when the shivers set in. Daylight shines through a gap in the cave wall, turning the Grotta Verde near the Marina di Andrano into an emerald chamber. Swimming here is magical.