I. On Salisbury Plain in Southern England stands Stonehenge, the most famous of all megalithic sites. Stonehenge is unique among the monuments of the ancient world. Isolated on a windswept plain, built by a people with no written language, Stonehenge challenges our imagination. The impressive stone circle stands near the top of a gently sloping hill on Salisbury Plain about thirty miles from the English Channel. The stones are visible over the hills for a mile or two in every direction. Stonehenge is one of over fifty thousand prehistoric "megalithics" in Europe. As Stonehenge is approached, the forty giant stones seem to touch the sky. Most