Windmills were hardly rare in Wales, likely in fact, to have been somewhat ubiquitous from Medieval times onwards, especially in the Marcher areas of the Country. Medieval windmill sites are now, however, largely identifiable only through the lumps and bumps of earthworks, place name evidence or, if we are lucky, in the records of the monasteries that often held them.
Groes Onnen Windmill is certainly not a medieval building - more likely a late 18th century, early 19th century building. But it is possible that it stands on the site of what was once a medieval windmill, owned by Basingwerk Abbey. Such a possibility is certainly logical, even likely given the amount of other properties owned by the Abbey in the locality.
Today Groes Onnen is a rare example of a windmill at full height, if devoid of its sails, of course. It is now a restored, residential property and grade II listed. A local landmark, visible as one enters the town along the A5026, it remains a wonderful example of our more sustainable past.
Further Reading
R. Hankinson & R. J. Silvester, Mills and Milling, CPAT Report No. 1174, (2012)
E. Hubbard, The Buildings of Wales Clwyd, Penguin, (1986)
D. H. Williams, Atlas of Cistercian Lands in Wales, Cardiff, (1990)
D. H. Williams, The Welsh Cistercians, Gracewing, Leominster, (2001)
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