Luke Winter holds a stone age axe as he works on a neolithic house recreation at Old Sarum, Wilts. Volunteers are helping English Heritage test build three neolithic houses at Old Sarum, Wiltshire - in their final form they will form part of an exhibition at the new Stonehenge visitor centre. They are being modelled on the ruins of the biggest Neolithic settlement ever found in Northern Europe at Durrington Walls around two miles from Stonehenge.