To the north west of Stone Arthur is the valley of Tongue Gill, separating it from the lower slopes of Seat Sandal. This side of the ridge is craggy with the main features being Brackenwife Knotts and Rigg Crags. Both Tongue and Greenhead Gills are tributaries of the River Rothay, which passes through Grasmere village to the lake of Grasmere. The lower slopes have been planted with areas of woodland.