Liddesdale, the valley of the Liddel Water, in the County of Roxburgh, southern Scotland, extends in a south-westerly direction from the vicinity of Peel Fell to the River Esk, a distance of 21 miles (34 km). The Waverley route of the North British Railway runs down the dale, and the Catrail, or Picts' Dyke, crosses its head. Liddesdale is sometimes considered to form the northern end of the Maiden Way Roman road.