The Blue Grotto is a sea cave on the coast of the island of Capri in southern Italy, which passes through an underwater cavity and shines through the sea water, creating a blue reflection that illuminates the cave. The cave extends about 50 meters into a cliff on the surface, is about 150 meters deep, and has a sandy bottom. This cave is considered one of the natural wonders of Italy, to which excursions are organized periodically.