Well, yeah, that’s pretty much why it was built. Stonehenge was constructed to calculate the moment of sunrise and moonrise over an 18.6-year cycle. By standing in the center of the circle you can face the sunrise (or moonrise) and foretell the season according to its position behind the “markers.” As an engineering feat, Stonehenge compares with the Great Pyramid. Yet it requires an effort of imagination to grasp the sheer magnitude of the conception, and the effort of willpower it represents.
The great uprights of Stonehenge—the sarsens—weigh fifty tons each. Thirty of these, surmounted by massive lintels, were originally arranged in a thousand-foot circle. (I remember it well.) Inside this there was another circle consisting of sixty “bluestones,” each weighing about five tons; and inside this, a horseshoe, also of bluestones. Between this there was another horseshoe of five vast trilithons. Even today, it would tax the ingenuity of a construction engineer to transport the fifty-ton sarsens. The megaliths were cut from outcrops of rock twenty-four miles from Stonhenge. Since the builders were farmers, who would not be able to spare more than a few months each year for these immense labors, it probably took most of two generations—forty or fifty years—to move all sixty stones. But even when they were finally on the site, the labor had only just started. Sarsen is so hard that it’s impervious to most modern steels. The great stones had to be shaped and smoothed by being pounded with other stones. Then came the dangerous task of erecting them into position. Need I go into the detail of that?
But wait. We still have to drag the seventy-nine five-ton bluestones, and the nearest quarry of them is 135 miles away! Again, it must have taken hundreds of men and decades of time… However, the snow on Salisbury Plain is deep in the winter, and the stones could have been dragged up long ramps of snow. (I hurt my back, let me tell you.) For a long while Stonehenge was thought to have been built around 1500 BC, but modern dating techniques have put that date back to around 3100 BC.
