A massive circular structure at the bottom of the Sea of Galilee (Israel) has puzzled  researchers who have been unable to excavate it. Now archaeologists are trying to raise money to allow them access to the submerged structure, which is made of boulders and stones. The monumental structure, with a diameter of 230 feet, emerged from a routine sonar scan in 2003.
     Archaeologists said the only way they can properly assess the structure is through an underwater excavation, a slow process that can cost hundreds of thousands of dollars. "It's very enigmatic, it's very interesting, but the bottom line is we don't know when it's from, we don't know what it's connected to, we don't know its function," said Dani Nadel, an archaeologist at the University of Haifa who is one of several researchers studying the discovery. "We only know it is there, it is huge and it is unusual."
     Much of the researchers' limited knowledge about this structure comes from the sonar scan a decade ago. In an article published earlier this year, Nadel and fellow researchers disclosed it was asymmetrical, made of basalt boulders, is cone-shaped structure and lies at a depth of between three and nine and 40 feet beneath the surface, about 1,600 feet from the sea's southwestern shore. Its base is buried under sediment. The authors conclude the structure is man-made, made of stones that originated nearby, and it weighs about 60,000 tons. The authors write it "is indicative of a complex, well-organized society, with planning skills and economic ability."
     Yitzhak Paz, an archaeologist with the Israel Antiquities Authority who is involved in the project, said that based on sediment buildup, it is between 2,000 and 12,000 years old. Based on other sites and artifacts found in the region, Paz places the site's origin some time during the 3rd millennium BCE, although he admits the timeframe is just a guess.
     Archaeologists were also cautious about guessing the structure's purpose. They said possibilities include a burial site, a place of worship or even a fish nursery, which were common in the area, but they said they wanted to avoid speculation because they have so little information. It's not even clear if the structure was built on shore when the sea stood at a low level, or if it was constructed underwater.
     In order to fill in the blanks, archaeologists hope to inspect the site underwater, despite the expense and the complexities. "Until we do more research, we don't have much more to add," Nadel said. "It's a mystery, and every mystery is interesting."

Edited Associated Press, NY Daily News (24 May 2013)