The corn mill at Russagh is a different matter. Sitting on a tributary of the Ilen river roughly two kilometres south-east of Skibbereen, this three-storey gabled structure retains its internal gearing and machinery in intact condition, which puts it in rare company among rural industrial survivors anywhere on the island.

The mill is a composite building: the original structure was joined by a matching three-storey gabled addition to the north at some point in the late nineteenth century, and a residential house sits to the west, suggesting the whole complex once formed a working farmstead built around the milling operation. The mechanical arrangement was a fairly typical one for a water-powered corn mill of the period. A mill race, a channel cut to divert water from the river, fed a wheel housed in a pit along the eastern gable, measuring just under 1.7 metres wide. The iron axle and its flaunch, the flanged collar that connected the axle to the wheel, are still present in the pit, along with the remains of the wooden arms that once formed the wheel itself. Inside, a pinion shaft, a small toothed gear engaging with the main wheel, drove a lying-shaft, a horizontal transmission shaft running along the interior, which in turn powered two pairs of millstones on the first floor. A lathe on the second floor drew power from the same source, suggesting the mill served more than simple grain-grinding and may have undertaken small-scale woodworking or maintenance tasks on site. The mill race to the east has been recently disturbed, which is a reminder of how quickly the water-management infrastructure around old mills can be altered or lost even when the building itself survives.