Original: Different pottery types such as Grooved ware appear during the later Neolithic (c. 2900 BC   c.2200 BC) whilst new enclosures, called henges were built, along with stone rows and the famous sites of Stonehenge, Avebury and Silbury Hill reached their peak.
Simplified: New enclosures, called henges were built, along with stone rows and the famous sites of Stonehenge and Silbury Hill reached their peak.