A Neolithic stone circle and subsequent henge is located at the eastern end of the Stonehenge avenue (Monument Number 858883), beside the river Avon. Excavations in 2009 by the Stonehenge Riverside Project discovered nine pits, or stone settings, making an arc which probably formed part of a larger stone circle measuring perhaps 10m across and thought to have been erected around 3000 BC. Some of the pits contained small bluestone chips which prompted the name `Bluestonehenge?. Charcoal and antler picks were also found. In about 2500 BC the stone circle was dismantled, with the bluestones possibly moved to Stonehenge (Monument Number 219434) and then around 2400BC and a henge ditch, about 25m in diameter, and outer bank were constructed. There do not appear to be any significant solar or lunar orientations within the monument.