My absolutely favorite place that I visited in England. Avebury is a Neolithic megalithic henge. It had 180 upright stones. There is a large outer circle, with two smaller inner circles. There is a massive circular mound surrounding it all with an interior ditch. It gives an amazing view of the surrounding countryside. There is a village and church within the structure. It was believed that building a church would cleanse the area of evil spirits.
It's located 30 km north of Stonehenge. Now Stonehenge is amazing but Avebury is so much bigger plus one could actually get quite close to the stones and walk on parts of the exterior dirt mound. The labor on the ditch and mound must have been amazing. I have a post card of an aerial view which shows the entire area.