MOSCOW – A Russian archaeologist claimed Tuesday to have found the well-preserved ruins of a "Caucasian Stonehenge" built by a previously unknown Bronze Age civilization in southern Russia.

Andrey Belinskiy said that unusual circular settings made of stones were found at one of some 200 settlements that date back to 1600 B.C. and are located in the North Caucasus mountains. The settlements have been uncovered in the past five years by a Russian-German expedition he heads, Belinskiy said.

He referred to the structure as a "Caucasian Stonehenge," drawing a comparison with the famous monument in southwest England....