A site I have visited many times, Avebury is amazing. It is the largest stone circle of them all and once had two smaller circles inside it that were the fifth and sixth largest. Around the outside is a massive henge, an earth mound inside which is a ditch. The mound now 15 feet high, used to be much taller and the ditch which is now 12 feet deep used to be more like 30 feet. It is still very impressive.
The top photo shows two of the main circle stones. The one on the left is the Devil’s Chair, so called because of the seat in the stone. It weighs some 60 tons, is 14 feet wide and 13 feet tall, and is placed so as to view the rising sun on the Winter Solstice.