For a cosy addition to a trip to the Lake District the Derwent Pencil Museum is lovely. It will teach you about the history of pencils in the area and how graphite was discovered! Inside they have carefully restored machinery, art workshops and more so you can get fully involved in pencils!
Also in the Museum is the Derwent Pencil Shop which has their full range of pencils so nothing is too specific to look for! They also have a lovely café with great cakes and coffee to round off your visit. The Museum is all weather, which is important in the Lakes as it rains a lot, and is great for all the family.