ITALY | Wednesday, 20 April 2011 | Views [542]
Light comes from two sources. One is a small hole in the cave wall at the waterline, that is perhaps a meter and half in diameter & barely large enough to admit a tiny rowboat. 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.
