Built 1710 for Sir George Thorold who was Lord Major of London 1719–20.
Estate sold 1898 to Nathaniel Clayton Cockburn, a grandson of Nathaniel Clayton, the Lincoln iron founder.
Bought by the Lincolnshire Joint Board for the
Mentally Defective, who opened it in 1935 as a 'Colony for Mental Defectives'.
Hospital closed in 1989 and is now a private residence.
DB 3 April 2018
Harmston, Hall, Sir George Thorold, Clayton, Lincolnshire Joint Board for the Mentally Defective