One of the best preserved and largest ancient monuments in Europe, Avebury has stood for aroud 5000 years since its original makers quarried its stones and erected them for reasons we can no longer know.
The site is marked by a circular ditch which is almost a mile in circumference. Within this ditch are 3 concentric circles of standing stones - the largest of which stand up to 16ft tall. There is also an 'avenue' of stones which curve away from the main circle, but many of the stones have been lost over the millennia and the purpose of this avenue can only be guessed at today. It is thought that perhaps they connected the site with another circle known as The Sanctuary, which stands atop a nearby hill.
Like many such monuments, there appear to be several astronomical alignments. Until its destruction the 18th century, a large stone called the "Obelisk" cast a shadow somewhat akin to that cast by a sundial and was thought to mark the passing of the seasons.
Another small formation of 3 stones known as The Cove is thought to have aligned with the midsummer sunrise.
Less astronomically, the stone known as "the Devil's chair" has a hollow in which you can comfortably sit, even if you aren't actually a demon or harbinger of evil.
As Avebury is so close to other sites such as Silbury Hill, it is thought that the area as a whole had some kind of large religious significance.