Above all, for fame and charm, the famous Blue Grotto stands out which is a natural ravine, of about 1,500 square meters, which is accessed through a very low passage, where, upon entering it appears almost all dark, but immediately after the eye used to it seems to have entered a blue and transparent cloud, suspended between Heaven and Earth. The blue color of the cave is an incredible effect which is called "refraction". This effect is determined by sunlight which, through a submerged opening under the entrance passage, is filtered and allows only the intense blue to pass through it, which for nearly two hundred years has stunned tens of millions of visitors, including some privileged have even bathed inside.
Swimming in the Blue Grotto, according to those who made this dream come true, is undoubtedly one of the most beautiful experiences you can have. Many people waits in the evening, when the boats leave, to be free to swim and enjoy such incomparable beauty.