Barr Castle, known locally as Lockhart Tower, is a substantial fifteenth-century tower fortress built between 1400 and 1542 on a prominent rock in the center of Galston, Ayrshire. The five-story tower with thick stone walls measuring approximately forty-eight feet by thirty-five feet was constructed by the Lockhart family, an ancient Scottish lineage first recorded in 1297. Over the centuries following the Lockharts' departure in 1670, the castle served multiple functions including jail, hospital, wool store, and church, reflecting its important place in the community. Today it stands as a tangible reminder of late medieval Scottish military architecture and the enduring heritage of a prominent Scottish family.