A former stronghold of the Stewarts in Dumfries and Galloway, Castle Stewart lies just west of the River Cree, 3 miles (5 km) northwest of Newton Stewart. Built in the early 16th C., this tower-house is partially ruined but still stands to four storeys. It was surrounded by a courtyard containing ancillary buildings, but these are not fragmentary. B-listed in 1979, the castle was named after Colonel William Stewart, a son of Lord Ochiltree, who made a fortune as a mercenary soldier fighting under Gustavus Adolphus of Sweden in the 1630s. On his return to Scotland he bought the estate which was then called Calcruchie.
Ravenstone Castle, located 16 miles (25 km) south, was also once known as Castle Stewart.