Being at the meeting point of three ridges, Hart Crag also has a share in three valleys. Despite forming a part of the headwall in each case, the fell is not the true head of any of them. West of the summit runs the long and unfrequented valley of Rydal Beck. This flows almost due south for 3 miles, finally emptying into the River Rothay at Rydal village. The slopes of Rydal Head below Hart Crag are steep, but reasonably free of outcropping rock.