Beneath a field bank in the townland of Park, County Waterford, there lies a piece of ancient milling technology that has survived not in a museum case but in the ground where it was first laid. During drainage operations on a small west-to-east stream near its headwaters, workers uncovered a wooden flume, a channel designed to direct a fast jet of water onto a mill wheel, carved entirely from a single piece of oak. It remains in situ to this day, an accidental piece of industrial archaeology preserved by the waterlogged conditions of a field boundary.

The flume itself is modest in its dimensions, roughly forty-five centimetres wide, fifteen centimetres deep, and with around one and a half metres still visible, yet what it represents is considerably larger in significance. It is associated with a horizontal-wheeled mill, a type of early water mill common across early medieval Ireland and sometimes called a click mill. Unlike the more familiar vertical waterwheel, the horizontal mill used a wheel laid flat beneath the millstone, spun directly by a concentrated jet of water funnelled through precisely such a flume as this. The technology was simple, effective for small-scale grain processing, and well suited to the modest upland streams of rural Ireland. The use of a single oak trunk to form the flume points to considerable craft, since the timber had to be shaped and hollowed to precise tolerances to produce the necessary pressure and flow.