Brim Fell is unusual in having no footing on the valley floor on either side of the ridge. On the east its boundary streams converge at 800 ft and the flanks of Coniston Old Man and Wetherlam continue to the lake. Above the Duddon, Brim Fell is nipped off by Dow Crag and Grey Friar at an even greater altitude. The area of the fell is therefore small, but full of interest.