At Mountprospect in County Kildare, a set of earthen banks traces out an ancient agricultural grid across the northern foot of a long pasture slope, quiet enough that most people passing through would never register it as anything more than uneven ground. What they are looking at, in fact, is a carefully organised field system, its layout preserved in low ridges of earth that have survived centuries of grazing and weather.

The system covers a large rectangular area roughly 350 metres from east to west and about 150 metres from north to south. A principal bank runs along the northern boundary, broad and low, between four and seven metres wide but rising only twenty to forty centimetres above the surrounding ground. From this main bank, a series of shorter banks branch off perpendicularly to the south, dividing the interior into smaller rectangular plots averaging around forty metres in length and twenty metres across. The overall impression is of a planned subdivision, the kind of orderly parcelling out of land associated with intensive agricultural management. The field system sits immediately west of a tower house, one of the fortified stone residences that the Hiberno-Norman and Gaelic Irish lordly classes favoured from the late medieval period onward, with a second, unclassified building lying roughly seventy-five metres to the north. The proximity of working fields to a defended residence is exactly the domestic and economic arrangement you would expect, the land organised around the needs and authority of whoever held the tower. Aerial photographs taken in 1970 first brought the extent and regularity of the earthworks into clear focus.