To the north of Wetherlam is the Greenburn Valley, a feeder of Little Langdale. A steep sided, rather marshy valley, Greenburn's waters join the River Brathay at Little Langdale Tarn. Greenburn itself bears a tarn, or more correctly the remains of a reservoir. A natural waterbody was dammed in the early 18th century to provide water for the Greenburn Mine. The 250 yard long barrage has now been breached to leave a collection of pools and bogs. Greenburn is bounded to the north by the curve of Wet Side Edge, falling from Great Carrs.