The Vale of York is often supposed to stretch from the River Tees in the north to the Humber Estuary in the south. More properly it is just the central part of this area which is truly the Vale of York, with the Vale of Mowbray to its north and the Humberhead Levels to its south. It is bounded by the Howardian Hills and Yorkshire Wolds to the east and the Pennines to the west. The low-lying ridge of the Escrick moraine marks its southern boundary. York lies in the middle of the area.