The Blue Grotto is a sea cave on the coast of the island of Capri, in southern Italy. It is a tourist attraction on the island and for day trippers from Naples and the Amalfi coast.  This very brief video shows you what you'll experience on a Blue Grotto tour.  You'll be pulled into the cave on a small boat and serenaded by your captain for about a minute while you float over the bluest water you've ever seen.