 A team of experts from the National Institute of Anthropology and History (INAH) has discovered a link between two systems of flooded caverns that together form the world’s largest underwater cave. Last Wednesday, after ten months of work, the Underwater Exploration Group of the Great Maya Aquifer Project (GAM) found a connection between two of the most extensive flooded cavern systems on Earth—Sac Actun and Dos Ojos, both in Mexico's Yucatán Peninsula—now forming the world's largest known flooded cave, with a length of 215 miles. "This immense cave represents the most important submerged archaeological site in the world, since it has more than a hundred archaeological contexts, among which is evidence of the first settlers of America, as well as the extinct fauna and, of course, of the Maya culture," says Guillermo de Anda, a National Geographic explorer and director of the GAM. Together, this pair of vast limestone wormholes add up to 216 miles of below-the-surface space - a number which makes their combined size greater than that of the Sistema Ox Bel Ha (also in eastern Mexico; 168 miles), which was previously thought to be the yardstick for underwater networks.
– For Robert Schmittner, it was a long time coming. "I didn't rest for 14 years," the diver tells Mexico News Daily. Schmittner is the director of exploration for the Great Maya Aquifer Project, which on Jan. 10 discovered the longest underwater cave on Earth. Divers for the project made the discovery by confirming something that—as per the Telegraph—had been long suspected: the 163-mile-long Sac Actun system and 83-mile-long Dos Ojos system of Mexico's Yucatan Peninsula are actually connected. Sac Actun's underwater cave system now absorbs Dos Ojos, becoming the record-setting, 216-mile-long Sac Actun system, Reuters reports. According to National Geographic, it's now 49 miles longer than the previous record holder and could get even bigger as divers continue to seek connections to other flooded cave systems in the area. "This immense cave represents the most important submerged archaeological site in the world, since it has more than a hundred archaeological contexts," the project's director, Guillermo de Anda, says. Those contexts include extinct animals and possibly signs of the first American settlers, but also new information about the ancient Maya civilization. “It allows us to appreciate much more clearly how the rituals, the pilgrimage sites, and ultimately the great pre-Hispanic settlements that we know emerged,” de Anda tells Reuters. Sinkholes leading to underground caves had religious significance to the Maya, and de Anda's project has found ancient walls, staircases, and paintings in some of the caves that aren't completely flooded. (A skeleton found in an underwater cave is one of the oldest in the Americas, so it's too bad thieves stole it.)