Largest flooded cave discovered in Mexico

Underwater archaeologists in Mexico have discovered the worlds largest flooded cave, a report said.

The Great Maya Aquifer Project (GAM) team spent years exploring the caves of Sac Actun and Dos Ojos studying the mysterious waters of Mexico's Yucatan peninsula in Tulum.

They have now been able to connect the two caverns together, the CNN reported.

The discovery marks the identification of an "incredible" archaeological site, illuminating the stories and rituals of the lost Mayan civilisation.

According to the rules of caving, when two caves connect, the largest absorbs the smallest. This means Sac Actun takes the title of largest cave, the CNN report said.

The watery  labyrinth spanning 347 km is a stunning web of underwater grottoes.

Now the goal would be to connect Sac Actun with three other local underwater cave systems, Guillermo de Anda, GAM director and researcher at the National Institute of Anthropology and History, said in a statement.

"This immense cave represents the most important submerged archaeological site in the world, as it has more than a hundred archaeological contexts," de Anda said.

"Along this system, we had documented evidence of the first settlers of America, as well as extinct fauna and, of course, the Mayan culture," CNN quoted de Anda as saying.

The Maya regarded their caves as a place to communicate with their gods -- so it was likely significant discoveries would be uncovered in the bowels of San Actun.

The next phase would involve analysing the water quality, investigating the biodiversity and continuing to map out the submerged maze of caverns.