The largest known flooded cave on earth has been discovered in Mexico by a team of divers after a project lasting almost a year.
Those working for the Great Maya Aquifer Project started exploring cavern systems in March last year.
The team has now connected two cavern systems, which together constitute a monolithic network called the Sac Actun System.
However the exploration director Robert Schmittner has actually been searching for the connection for 14 years, according to the project's own website.
Previously the largest known flooded cave was the Ox Bel Ha System, which is also in Mexico, measuring 270 kilometres.
The Sac Actun System has now been found to measure 347 kilometres. But the work is not yet complete, as researchers still want to discover whether it is connected to any other systems.
Research of the cave will also continue to look at the quality of water inside it and the biodiversity it supports.
Schmittner said this research has been going on for more than 20 years in the Mexican state of Quintana Roo and it's everyone's responsibility to continue the investigation.
The caves are said to be of historical importance as they hold archaeological details such as preserves from the Mayan culture and extinct fauna.
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