An atoll is the ring of coral islands which were formerly around an island which has since disappeared due to erosion or volcanic activity. Basically what you have left is a vaguely ring shaped group of islands with a lagoon in the center and ocean all around.
On the island I was on you walked to one side of the island and watched the surf roll. Then you crossed the island (about the width of a parking lot) and sat in the calm warm lagoon. Too heavenly!
On the island I was on you walked to one side of the island and watched the surf roll. Then you crossed the island (about the width of a parking lot) and sat in the calm warm lagoon. Too heavenly!
Not sure if I was the first on "on" it though. 
