The Blue Cave is a noted sea cave on the coast of the island of
Capri,
Italy. Sunlight, passing through an underwater cavity and shining through the seawater, creates a blue reflection that illuminates the cavern.
Color
The Blue Grotto is one of several sea caves, worldwide, that is flooded with a brilliant blue or emerald light. The quality and nature of the color in each cave is determined by the unique lighting conditions in that particular cave.
In the case of the Blue Grotto, the light comes from two sources. One is a small hole in the cave wall, precisely at the waterline, that is a meter and half in diameter. This hole is barely large enough to admit a tiny rowboat, and is used as the entranceway. In photographs taken from within the cave, the above-water half of this hole appears as a spot of brilliant
White light. The second source of light is a second hole, with a surface area about ten times as large as the
First, which lies directly below the entranceway, separated from it by a bar of rock between one and two meters thick. Much less light, per square meter, is able to enter through the lower opening, but its large size ensures that it is, in practice, the primary source of light.
In part because of the dazzling effect of the light from the above-water opening, it is impossible for a visitor who is in one of the row-boats to identify the shape of the larger hole, the outline of the bar that separates the two holes, or even the nature of the light-source, other than a general awareness that the light is coming up from underneath, and that the water in the cave is more light-filled than the air. A visitor who places a hand in the water can see it "glow" eerily in this light.
Visiting the Blue Grotto
The Blue Grotto can be reached by motorboat from the port of Marina Grande, by bus from
Anacapri, or by taxi. To enter the low opening to the grotto, the
Tourist transfers from the motorized boat that brought him or her from the port into a small wooden rowboat manned by one of the oarsmen who specialize in ferrying travellers into the cave. Because there is no headroom, visitors must lie on their backs in the bottom of the rowboats as they clear the entranceway. The interior of the grotto is quite spacious, and once inside it is possible to sit upright, until conveyed back out through the same tiny hole.
The grotto cannot be visited during adverse weather conditions, as the entrance is barely large enough to accommodate the small rowboats, and waves can cause the gunwales of the small boats to be smacked upwards against the roof of the opening. As well, bright sunlight is necessary to create enough light to cause the interior of the cave to be lit up in the brilliant blue color for which it is so famous.
Cultural influence
The cave is highlighted in the 1953 Newbery Medal book, Red Sails To Capri, by Ann Weil.
