The list shows us that after all this time trying to create wonderful Obra Maestras, Mother Earth still beats us at making the most awe-inspiring creations. Doesn't it make you feel bad for taking our environment for granted and polluting it continuously?
Blue holes are giant and sudden drops in underwater elevation that get their name from the dark and foreboding blue tone they exhibit when viewed from above in relationship to surrounding waters. They can be hundreds of feet deep and while divers are able to explore some of them they are largely devoid of oxygen that would support sea life due to poor water circulation - leaving them eerily empty. Some blue holes, however, contain ancient fossil remains that have been discovered, preserved in their depths.