The Derwent Valley World Heritage Site nomination contains within its 24 kilometres (north to south) four industrial settlements. It extends from the edge of Matlock Bath and Cromford in the north and almost to the centre of the city of Derby in the south. The industrial settlements which are included are Cromford, Belper, Milford and Darley Abbey. The spine linking the settlements which contain the principal industrial monuments within the site is the river. Historically it was the water power which the Derwent and its tributaries offered that provided the raison d’être for the growth of these settlements.