The Blue Hole is an underwater cave off the coast of Belize which has long attracted divers and tourists. Now, rock samples collected at the feature, as well as nearby lagoons, could answer one of the great mysteries of archaeology.

The ancient Mayan civilization existed for thousands of years in Mesoamerica - the areas now occupied by Mexico and Central America. The people here developed their own system of hieroglyphics, as well as advanced mathematics for their time. The calendar developed by the Maya named dates ten centuries ahead of the time it was developed. This is the calendar which made popular news in 2012, when some people claimed the dating system predicted the end of the world.

The ancient Mayan civilization collapsed in the ten decades between the years 800 and 900 of the Common Era, and the population fled the cities. Scattered remnants of the once-mighty society were seen again in surrounding areas as rains returned to normal levels 11 centuries ago.

The earliest-known Mayan artifacts date from around the year 1800 B.C.E. In the opening centuries of the Mayan civilization, the people spoke just a single language. During their Preclassic Period, which ended in the year 250 C.E., many different languages appeared in the society. Today, approximately five million people living in South and Central America still speak about 70 languages first heard in the time of these ancient people.

Ancient Mayans built massive pyramids and were able to develop sophisticated naked-eye astronomy. In many ways, they were far in advance of other civilizations of their time in the region. The earliest Maya were mostly farmers, living in an agricultural society. By the third century of the Common Era, these farmers had started to farm the hills surrounding their enclaves, as well as valleys in the region.

Populations began to leave their cities after the year C.E. 700, a process which continued for more than a century. Wars became common and building ground to a standstill.

By the year C.E. 900, most of the cities once populated by vast numbers of Mayans were abandoned. Archaeologists have been unable to uncover evidence of war or sudden disaster. Some researchers speculated the loss of favorite foods, such as Tikal deer, may have driven people from their homes. Other investigators suggested deforestation could have created an environmental disaster. Even the fear of evil spirits was thought, by some, to play a role in the civilization's demise. Drought, however, was also a popular theory, now backed up by new research.

Researchers collected sediment from core samples drilled around the region, finding evidence a massive drought struck the area during the time of the societal collapse.

"When you have major droughts, you start to get famines and unrest," André Droxler of Rice University, head of the new study, said.