Scientists were amazed to find a Stonehenge-like structure dating back 10,000 years in waters off the coast of Sicily, and they say it may help them learn more about the ancient peoples of the Mediterranean Basin.

The monolith was found in 131 feet of water and is about 3.2 feet long, broken into two parts with a regular shape and three holes of about equal diameter, according to a Discovery News report.

The features on the rock indicate it couldn’t have been made by natural processes and could be in the range of 10,000 years old. A team of researchers from Tel Aviv University in Israel and the National Institute of Oceanography and Experimental Geophysics in Italy made the discovery and published a paper on it in the Journal of Archaeological Science.

These scientists believe that although the rock sits in 131 feet of water, it is actually in a location that was once a small island in the Sicilian Channel called Pantelleria Vecchia Bank. It is named after the volcanic of Pantelleria, which is about 24 miles away. Scientists think that a huge flood about 9,500 years ago submerged the island during the Last Glacial Maximum, when sea levels rose and completely changed the geography of the Mediterranean Basin forever.

In fact, there was like an archipelago populated by ancient peoples, who undoubtedly colonized and settled many of these islands. The islands would have benefited from having a mild climate and a good location between Europe and Africa.

This discovery is especially amazing because it shows how technologically advanced these peoples were during the Mesolithic era. Because this Stonehenge-like monolith weighed about 15 tons and was made from a single block, it would have required incredibly technical skills in cutting, extraction, and perhaps especially transportation, scientists believe.