An abutment is the point where an arch (in a horizontal or vertical direction) or vault meets its solid support. For a bridge or dam this might be on the riverbanks or a pier projecting into the river. The failure of the abutment may mean the collapse of the bridge, (such as at Hexham, see Smeaton, John). There is a Roman example at Chesters Roman bridge, Northumberland, east side of the North Tyne, (a free English Heritage site). The Hexham bridge abutments are of historical importance - being the last bridge that Smeaton designed.