Close to the village of Conca dei Marini, stairs and an elevator descend to a marine cave. You may wonder how a sea cave came to have stalactites, but this one wasn't always at sea level.
The cave was formed higher, but the region's volcanic activity (you're not all that far from Vesuvius here) changed the sea and ground levels and put the cave where the sea could wash in.
Like the Blue Grotto in Capri, sunlight shining through the water causes it to look as though it were lit from within, in this case in an emerald green glow.
The water is so clear that it is possible to see through to the bottom. Boats wait at the cave entrance to take you inside, or you can take a boat to the cave from the beach in Amalfi, about a 15-minute ride.
