The deep sea can reveal lots of never-before seen animals and other marine life forms from whale-eating scavenger shrimps to multicolored corals to a structure that represents ancient civilization.

Underwater off the coast of Sicily lies an ancient monolith that is structured similarly to the Stonehenge.

Archaeologists found the ancient structure broken in parts, about 3.2 feet long and with a regular shape. The structure has three similarly-sized holes - one at the end, which crosses it from part to part, and the other two at the two sides of the huge stone structure. The monolith is situated deep under water at a depth of 131 feet.

According to Zvi Ben-Avraham at Tel Aviv University's Department of Earth Sciences and Emanuele Lodolo from Italy's National Institute of Oceanography and Experimental Geophysics in Trieste, there are no possible natural occurrences that may have led to the formation of the structure, to their knowledge.

Lodolo also noted that the structure weighs some 15 tons and was made from a single block of stone that was cut, extracted, transported and installed. This sheds light on the technical and engineering skills ancient humans applied to build the monolith. 

The researchers said that the monolith's features could have only been made by humans, more or less 10,000 years ago. They further describe their findings published online in The Journal of Archaeological Science.

The area where the Stonehenge-like monolith lies used to be an island called Pantelleria Vecchia Bank in the Sicilian Channel, about 24 miles north of the volcanic Pantelleria island. Massive flooding some 9,500 years ago caused the structure to be submerged under water, and altering the geography of the entire Mediterranean Basin following the Last Glacial Maximum.

The researchers have not yet determined what exactly the structure was built for. It could have functioned as a single structure, or may have been part of a bigger complex. They said, however, that the structure could have most likely been built to serve the functions of the settlement of Mesolithic inhabitants who had a knack for fishing and trading with neighboring islands.

"It could have been some sort of a lighthouse or an anchoring system, for example," added Lodolo.

"The Sicilian Channel is one of the shallow shelves of the central Mediterranean region where the consequences of changing sea-level were most dramatic and intense," the researchers wrote.