Stonehenge

This was a fascinating programme and it explained something that has bothered me for years. In 'Chariots of the Gods' the fraudster, Erich von Daniken, pointed out that there were long, dead straight lines on the ground in South America, which could only be seen from the air. There is something similar around Stonehenge, and it was explained that if there is a slight incline water will find its own level by the shortest route, and will travel in a straight line. So, no super aliens, just simple physics!