 The ruin of Cairns Castle, dating from around 1440 and built by George Crichton, is situated on an hillock which projects into the reservoir.At Harperrig Reservoir the fishing season runs from 15 March to 15 October and the fishing permits are administered and sold by Harperrig Fisheries Ltd, a company which represents the various owners of the fishing rights.Both boat and bank fishing are allowed and the reservoir is stocked with brown trout.