Maya Artifacts Found In World's Largest Underwater Cave

Remains of giant sloths and proto-elephants were found interspersed with burnt human bones and ceramics in Mexico's Sac Actun cave system.

Last month, researchers from the Great Maya Aquifer Project announced the discovery of the world's largest underwater cave system in Yucatán after realizing that two massive cave systems in the Mexican peninsula were connected. Now, they're unveiling the findings to the public.

"This immense cave represents the most important submerged archaeological site in the world," underwater archaeologist and National Geographic explorer Guillermo de Anda told National Geographic in January when the newly discovered system was announced. "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."

Ancient Remains

Researchers say the water level in the 215-miles-long Sac Actun cave system has likely fluctuated over time, providing a source of much-needed water during times of severe drought. For example, water levels rose more than 300 feet at the end of the Ice Age, flooding the cave system and preserving the remains of extinct megafauna. Humans likely didn't live in the caves, but probably visited them in search of water.

Explore the World's Largest Underwater Cave January 17, 2018 - The world's longest underwater cave has been discovered near the city of Tulum, on Mexico's Yucatán Peninsula. The new discovery connects two previously known flooded caves into one 215-mile-long stretch. The cave holds an important large fresh water reserve that supports great biodiversity. Hundreds of archaeological sites exist in the cave, including evidence of America's first settlers, Mayan culture, and extinct animals.

Click here to read World's Largest Underwater Cave Discovered.

In the system, underwater archaeologists found the 15,000-year-old remains of giant sloths, proto-elephants called gomphotheres, and bears, as well as an elaborate shrine to the Maya god of war and commerce.

More than 120 artifact sites such as burnt human bones, ceramics, and wall etchings have been found in the caves, some dating back more than 12,000 years. One human skull covered in rainwater limestone deposits is 9,000 years old, de Anda says.

Archaeologists have been exploring these cave systems for decades, and these latest discoveries are consistent with the human artifacts and megafauna previously found in the Yucatán's watery underworld. The enormous length of the massive Sac Actun system makes these new discoveries particularly remarkable.

"It is very unlikely that there is another site in the world with these characteristics," de Anda says in a statement. "There is an impressive amount of archaeological artifacts inside, and the level of preservation is also impressive."

Even so, experts warn that the Sac Actun cave system is threatened by pollution.