The ruined remains of Cessford Castle lie near the settlement of Cessford, 11 miles (18 km) southeast of Newton St Boswells in the Scottish Borders. Built around 1450 to an L-shaped plan, it was a stronghold of the Kerrs of Cessford, a sept of the Kerr clan, the family of the Dukes of Roxburgh and Marquesses of Lothian. Cessford has massive walls, some 4.2m (14 feet) thick and was once described as 'the third strongest fortification in Scotland'. It was regularly attacked by the English and the Earl of Surrey laid siege to the castle in 1523. It was surrendered and finally burned another invading army in 1543.
An important survivor of its period, the castle was re-opened by the Duke of Roxburghe in 2006 following a £300,000 restoration project.