Ammar Awad / REUTERS A man walks by the shore of Israel's Sea of Galilee at sunset.

Archaeologists are studying evidence of a 60,000-ton stone structure at the bottom of the Sea of Galilee in Israel that could denote an ancient burial ground.

The giant cone-shaped configuration is formed by basalt cobbles and boulders up to four feet in diameter and its base lies roughly 40 feet beneath the surface, reports CNN.

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Researcher Yitzhak Paz, of the Israel Antiquities Authority and Ben-Gurion University, told Live Science that the mound could date back more than 4,000 years. “The more logical possibility is that it belongs to the third millennium B.C., because there are other megalithic phenomena [from the same time] that are found close by,” he said.

Although researchers carrying out a sonar survey of the sea first discovered the 30-foot-tall ‘monument’ in 2003, divers have only now been down to investigate further. Their findings have just been published in the International Journal of Nautical Archaeology.

“This is such a huge structure that it truly is something unusual,” Dani Nadel, an archeologist from the University of Haifa, told CNN. “It could have been a big ceremonial structure, or a ramp. There could have once been statues on top of people in certain rituals. I mean, I’m really going wild here. The truth is we don’t know how it was constructed, what its exact age is, how it was used, or how long ago it was used. We have several speculations, but we don’t know much except that it’s there and it’s huge.”

Other explanations include the possibility that it was created below the surface as a fish nursery, as similar smaller structures have already been discovered that were built for that purpose.But the main theory is that the 230-f00t-wide structure — larger than a Boeing 747 — was built on dry land and then became submerged as the water level rose. Underwater archaeological excavations are now being planned in order to find associated artifacts that might reveal more about its true function, according to the Daily Mail.

The Sea of Galilee is actually a freshwater lake — the largest in Israel and lowest on the planet — and measures roughly 64 square miles with a maximum depth of 141 feet. It plays a key role in the New Testament — Jesus would often teach by its shores — and remains a major destination for Christian pilgrims.

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