River Nethan
The River Nethan flows between Glenbuck in Ayrshire and Crossford in Lanarkshire where it discharges its waters into the River Clyde.
The area of woodland surrounding the River Nethan at Crossford and Auchenheath has been declared a site of special scientific interest and forms a part of the Clyde Valley Woodlands National Nature Reserve as Nethan Gorge.
The town of Lesmahagow and surrounding villages sitting on the river course. Craignethan Castle, a 16th-century fortification, overlooks the river.