ALL

Capri's Blue Grotto is known throughout the world for its size, the intense blue tones of its interior and the magical silvery light which emanates from the objects immersed in its waters. Visitors to the Grotta Azzurra can arrive either by bus or taxi from Anacapri; or by boat from Marina Grande in one of the tour boats which stop at the entrance of the cave during the trip around the island. In order to enter the Grotta Azzurra visitors climb aboard small rowing boats, with a capacity for two, maximum three, passengers and, lying on the bottom of the boat, enter the low and narrow mouth of the cave. Entrance to the cave is not possible in the presence of south westerly and mistral winds.
The entrance to the Grotta Azzurra is formed by a small natural opening in the rocky wall, roughly 2 meters wide and 2 meters high. The roof of the entrance is situated approximately 1 meter above the level of the sea and, for this reason, passengers are obliged to lie down in the boat whilst passing in to the cave. The boatman sets down his rows and maneuvers the boat inside with the aid of a chain attached to the vault of the entrance.
The interior is effused with magnificent blue tones. The vault, known as the Duomo Azzurro, has an average height of 7 meters rising to 14 towards the back of cave. The erosion cavity is approximately 60 meters long and up to 25 meters wide. The cave continues with the Galleria dei Pilastri, three connecting branches which flow into the Sala dei Nomi, the name of which was inspired by the numerous signatures left by visitors on the walls of the cave. Then there is the Passaggio della Corrosione, and the Sala della Corrosione, the furthest accessible point.
The blue coloring of the Grotta Azzurra is created by the daylight which enters via an underwater opening located immediately below the entrance to the cave. The light is filtered by the water which absorbs the red tones, leaving only the blue ones to pass into the cave.
A second phenomenon creates the silver appearance of the objects immersed in the water: given that the index of refraction of the bubbles of air which adhere to the surface of the objects is different to that of the water, the light is allowed to egress.
It is believed that, in the Roman period, under the rule of Tiberius, the interior of the Grotta Azzurra was used as a marine nymphaeum. There have been those who imagined the cave as the habitat of Nereidi or of Sirens or believed it to be the realm of devils who bewitched all who dared to enter.