Gartmorn Lade, Forestmill

Gartmorn Lade in Forestmill is a notable weir designed by engineer George Sorocold in 1711-12 and rebuilt in 1835. This rare and striking horse-shoe plan weir is an early design created to direct water from the River Black Devon, which flows from east to west, through a sluice into the Forestmill Lade and return floodwater back over the top of the weir into the river. It was built as part of a water management system initiated by John Erskine, Earl of Mar, which includes sluices controlling the water flow to a 2.5-kilometer lade leading to Gartmorn Dam, the oldest reservoir in Scotland.

The weir is constructed from ashlar stone and features a raised platform made of large slabs arranged around a curve of squared stonework, which encompasses a deep basin seemingly set on bedrock. The sides of the weir slope down to the west, reaching a height of approximately 4 feet.