Remains of hundreds of 7,000-year-old 'standing stone circles' discovered in Saudi Arabia

Archaeologists in Saudi Arabia have excavated eight ancient "standing stone circles" that they say were used as homes. 

About 345 of these structures were identified through aerial surveys across the Harrat 'Uwayrid, a lava field near the city of AlUla in northwestern Saudi Arabia, the team reported July 2 in the journal Levant. The circles range from 13 to 26 feet (4 to 8 meters) in diameter and have at least one standing stone at the center. 

The circles date back around 7,000 years and have the remains of stone walls and at least one doorway. They would have had roofs made of either stone or organic materials, the team wrote. 

During their excavations, the archaeologists discovered the remains of many stone tools made of basalt. Five of the standing circles alone yielded nearly 500 pounds (225 kilograms) of stone tools or debris, the team wrote. The archaeologists also found the remains of bones from sheep, goats and cows. 

Also among the finds were a variety of seashells, all of which came from the Red Sea, which is located about 75 miles (120 kilometers) to the west. The presence of the seashells "suggests developing networks of trade and exchange, concurrent with mobility," the team wrote. 

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The artifacts found in the circles, combined with the circles' similarity to ancient homes excavated in Jordan, suggest that many, if not all, of the standing stone circles are also domestic structures, the team noted.