A huge, cone-shaped monument has been discovered by a team of Israeli archaeologists conducting a geophysical survey on the southern Sea of Galilee.
The monumental structure is made of basalt boulders. Fish, marked with arrow, is about 10 cm (Shmuel Marco)
According to a paper published in the International Journal of Nautical Archaeology, the structure was built several thousand years ago and later submerged under the water.
It is 230 feet (70 m) in diameter and about 39 feet (12 m) high. The estimated weight of the monument is over 60,000 tons.
The site resembles early burial sites in Europe and was likely built in the early Bronze Age. There may be a connection to the nearby ancient city of Beit Yerah, the largest and most fortified city in the area, explained Dr Yitzhak Paz from Ben-Gurion University, lead author of the paper reporting the discovery.
The stones, which comprise the structure, were probably brought from more than a mile away and arranged according to a specific construction plan, added co-author Prof Shmuel Marco from Tel Aviv University.
Proportions of the structure (Shmuel Marco)
The team initially set out to uncover the origins of alluvium pebbles found in this area of the Sea of Galilee, which they believe were deposited by the ancient Yavniel Creek, a precursor to the Jordan River south of the Sea of Galilee. While using sonar technology to survey the bottom of the lake, they observed a massive pile of stones in the midst of the otherwise smooth basin.
To estimate the age of the structure, the archaeologists turned to the accumulation of sand around its base. Due to a natural build-up of sand throughout the years, the base is now 6 to 10 feet below the bottom of the Sea of Galilee. Taking into account the height of the sand and the rate of accumulation, they deduced that the monument is several thousand years old.
Assuming an accumulation rate of 14 mm/yr, construction may have taken place between 2,000 and 12,000 years ago, the team wrote in the paper.
This sonar image reveals the structure as a circular heap of stones (Shmuel Marco)
The base of the structure which was once on dry land is lower than any water level that we know of in the ancient Sea of Galilee. But this doesnt necessarily mean that water levels have been steadily rising, Prof Marco said.
Because the Sea of Galilee is a tectonically active region, the bottom of the lake, and therefore the structure, may have shifted over time. Further investigation is planned to increase the understanding of past tectonic movements, the accumulation of sediment, and the changing water levels throughout history.
The archaeological team now plans to organize underwater excavations to learn more about the origins of the structure, including an investigation of the surface the structure was built on.