A steep and rough slope descends north east from the summit of Green Gable, dropping through Mitchell Cove to the flat-topped and rather damp col of Blackmoor Pols (1,995 ft). Beyond this the ground rises again to the steep sided dome of Base Brown. On the south eastern face are crags overlooking Styhead Gill with Seathwaite Fell across the valley. The north western flanks are equally steep, but descending only half the vertical distance into the hanging valley of Gillercomb. This is the gathering ground of Sour Milk Gill, which drops over a series of falls around the northern extremity of Base Brown. Here it joins Styhead Gill and Grains Gill to form the nascent River Derwent. Across Gillercomb is the main ridge continuing north around Ennerdale, Brandreth being the initial fell. The top of Base Brown narrows considerably to the north of the summit, a prow-like ridge descending toward the falls of Sour Milk Gill. There is a prominent hanging stone here, startlingly poised over the rim of the crags. Another feature is the Seathwaite Slabs, a set of slabs of rocks used for rock climbing practice by novices and conveniently located only minutes from Seathwaite.