"The site is generally dated to the 17th century BC. Earlier dates, up to the 20th century BC, have been proposed. It was a settlement of the Sintashta-Petrovka culture, associated with Indo-Iranians.
According to their claims, the Neolithic observatory at Stonehenge allowed for observation of 15 astronomical phenomena using 22 elements, whereas the contemporaneous observatory at Arkaim allowed for observation of 18 astronomical phenomena using 30 elements. The precision of measurements in Stonehenge is estimated at 10 arc-minutes to a degree, that in Arkaim being put at 1 arc-minute. Such a precision of astronomical observations was not repeated until the compilation of Almagest about 2 millennia later."