A curving ridge surrounds the head of Bannerdale, with Bowscale Fell at the northern end and Bannerdale Crags to the south. The ridgeline is broad and grassy with occasional patches of bog and a couple of small tarns in the north. Bannerdale flows due east from the depression between the two fells to its junction with the River Glenderamackin. A second tributary of the Glenderamackin, Bullfell Beck, runs parallel a little to the north, its source being directly beneath the summit of Bowscale Fell. The heads of the two valleys are divided by a truncated east ridge, The Tongue, which sports a top (1,814 ft) at the far end. From below, The Tongue appears as an impressive pyramidal peak with steep slopes on all sides, obscuring the higher ground behind.