English: Harrow: Headstone Manor. Headstone Manor is a Grade I listed building on a moated site now entirely surrounded by Headstone Recreation Ground. This view was taken across the moat bridge. Although the external facade is not remarkable, at the core of the building is part of an early 14th-century timber framed house, the only surviving example of a medieval aisled hall in Middlesex. The London Borough of Harrow owns the building, and repair and refurbishment works are in progress as the security fencing bears witness. The fabric of the structure has been analysed, and dendrochronology has revealed that the hall range and surviving cross wing were built c 1320.