The site of a medieval water corn mill just to the east of Parkmill, Gower. In the medieval period the mill lay in the manor of Lunnon, a sub-manor of Pennard. In the earliest surviving financial records for the lordship the mill does not appear by name. Several mills are accounted for and it is assumed that this is one of them, together with nearby Parkmill similarly unnamed (NPRN 24961). Both appear by name as `Parke Myll? and `Stone Myll? in the mid-sixteenth century and as `the Park Mills? in the seventeenth century (1). Stonemill was still in use in the late nineteenth century when it appeared on the Ordnance Survey first edition 25-inch map. Then, Stonemill was a hamlet to the east of Parkmill. The mill is shown with a mill pond fed by a leat from the Ilston river. It appears to have gone out of use early in the twentieth century. Since then it has undergone several episodes of re-use and is currently a dwelling.
The mill's location, immediately south of the deer-park of the de Braose lords of Gower, may offer clues to its origins. The eastern portion of the park (nearest the mill) was converted to a manorial farm, or grange (`Grangia de Lunan?), probably in the later thirteenth century (2). Fourteenth century accounts document the grain output of the farm; a grist mill located close by may thus have been required. A second grange, implied in early records but as yet unlocated, lay a kilometre or two to the south-east, in Pennard (1). Its output may also have been processed here.

(1) D.K.Leighton, `The demesne watermills of the lordship of Gower in the fourteenth century: a reappraisal?, Melin 21 (2005), 9-36.
(2) D.K.Leighton, `A fresh look at Parc-le-Breos?, Gower 50 (1999), 71-9.