Beneath the soil of a natural hillock known as Windmill Hill, beside Castleknock village, four gravecuts containing human skeletal remains came to light, quietly waiting in the earth just east of an existing water tower.

The discovery came during test excavation carried out in 2007 under licence number 07E0682Ext., led by McLoughlin, in advance of the planned infrastructure works. Gravecuts are precisely what they sound like, the deliberate cuttings made into the ground to receive a burial, and their presence here in a cluster suggests this corner of the hillock once served a funerary purpose, though the notes do not specify the period or community to which these individuals belonged. Faced with the finds, the development was redesigned to allow for preservation in situ, meaning the remains were left undisturbed in place rather than removed. A subsequent geophysical survey, carried out under licence number 07R233, added another layer to the story of the hill by locating the windmill that gives the place its name, recorded in the national monuments inventory as DU017-013002. The two discoveries together suggest Windmill Hill has a considerably denser history than its quiet, grassy appearance implies.

The site sits within the grounds of the Vincentian college at Castleknock, which means public access is not straightforward. The hillock itself is not a formal heritage site open to visitors, and the burials remain underground, preserved rather than displayed. Those with a particular interest in the area might find value in consulting the national monuments record for the geophysical survey results, which map the footprint of the windmill beneath the surface. The broader Castleknock area rewards some background reading before any visit, given how much of its archaeology remains below ground and out of sight.