The Blue Grotto (or Grotta Azzurra) is the most famous site on Capri, and it's easy to see why. The grotto is a natural sea cave with a small entrance, and it is illuminated in a blue and silver ...
The Blue Grotto on the island of Capri, in Italy; and the nearby Green Grotto on the Amalfi Coast, are other popular spots. Be sure that the sun is in in the correct position to illuminate the water.