 It provides a continuous homogenous landscape of high quality agricultural land, with a number of local variations.To the west of the Edge, the gently undulating Trent Vale eventually flows into the moors and levels of Humberhead, draining to the Humber Estuary.To the east there is a gentle transition into the Central Lincolnshire Vale between the Humber and Lincoln, while south of Lincoln the Edge is bounded by a narrow finger of Fenland, which follows the River Witham into Lincoln.