The area around Knowlton formed a major ritual site in the Neolithic period, the main focus being three Neolithic henge earthworks. Two have long since been ploughed and weathered away, but one remains with the ruin of a twelfth century Norman church at its centre, probably some form of controlling pagan sites by the early church.
The henge has entrances to the Northeast and the Southwest and is 12 feet high in some places. It may have had other structures such as tall wooden posts erected within it when it was in ritual use, although the site has not been fully excavated.
There is also a large round barrow known as the Great Barrow to the East of the henge, which is nearly 20 feet high, the barrow is now tree covered.