The Green Grotto Caves prominent tourist attraction. Named for the green algae that cover its walls, the structure of the cave.
The chambers have been carved by tides and waves with two well-defined levels apparently indicating two periods with differing sea-levels. The innermost cavern contains a crystal-clear underground lake. The cave system is connected with the adjacent coastal waters. The mammoth cave is full of rock formations, stalagmites, and stalactites and is filled with numerous chambers and light holes, but its most dramatic feature is eerie Grotto Lake, a subterranean lake occupying its bowels.