Scientists have made an amazing discovery off the coast of Sicily: a Stonehenge-like structure that is clearly manmade and could be 10,000 years old.

The mysterious monolith was found in the deep sea, and it could answer many questions about the earliest civilizations to have settled in the Mediterranean basin, according to a Discovery News report.

The monolith, which is about 3.2 feet long and broken into two parts, has a regular shape and three holes of similar diameter. These features indicate that the monolith is about 10,000 years old, and scientists have ruled out natural processes that could have produced such a feature.

A research team at Tel Aviv University in Israel and the National Institute of Oceanography and Experimental Geophysics in Italy published the study in the Journal of Archaeological Science.

The monolith was found 131 feet below the surface in area that was at one point above the water and would have been a small island in the Sicilian Channel. Scientists refer to it as Pantelleria Vecchia Bank, and it is about 24 miles north of Pantelleria, a volcanic island. A massive flood about 9,500 years ago submerged the island as part of an event that drastically changed the geography of the Mediterranean Basin, as sea levels rose during the Last Glacial Maximum.

Scientists believe that an ancient people probably colonized and settled various islands in what would have been an archipelago back then, especially with its good climate and advantageous position between Europe and Africa.

It’s an important scientific discovery that shows just how technologically advanced the Mesolithic inhabitants of this region were. The monolith weighs about 15 tons and was made out of a single block that would have required skilled cutting, extraction, and transportation.