The Great Blue Hole, Belize

The Great Blue Hole is located near the Lighthouse Reef atoll, in the Belize Coral Reef Barrier, the second largest coral reef system in the world after the Great Barrier Reef in Australia; it is considered one of the best scuba diving site in the world.

The hole is almost perfectly circular in shape, 300 meters wide and 120 meters deep. It was formed as a limestone cave during the quaternary glaciation (when sea levels were much lower), flooded after the oceans’ level raising.

Recently, some scientific studies, by analysis of the amount of aluminum and titanium deposited in the Great Blue Hole (lower levels of aluminum and titanium in soil and sediments correspond to periods with fewer precipitations) have demonstrated that between 800 d.C. and 1100 d.C. two periods of drought created the preconditions for the decline of the Maya civilization.