Wether Fell and Semer Water, South of Bainbridge in Wensleydale lies a small upland valley called Raydale which, with a 90 acres area, contains the largest natural lake in the Dales (Semer Water). From it flows the shortest river in the country, the two mile long River Bain, which joins the River Ure at Bainbridge. This 10 mile [black] walk (with only 1200ft of ascent) offers a varied mixture of open moorland grass pasture, good tracks and high rough moorland.