We don’t actually know that Avebury (Henge) was the main aim, in fact the lack of human activity in the archaeological record there (compared to the area around Silbury) would suggest that Avebury always remained somewhat aloof from the hustle and bustle of the Ridgeway. That’s not to say that Avebury was not an important arena for large gatherings at certain times of the year. In fact the Bank on the outside of the Ditch (where spectators might gather) and the Avenues leading to the Henge itself, suggest that large ceremonial gatherings did take place there... the rest of the time it might have been completely out of bounds to Joe Public.