Around the early church of St Begnet, in the north-western corner of Dalkey Island, a series of drystone walls and low earthen banks trace the edges of fields that were being cultivated before the thirteenth century. Drystone construction means exactly what it sounds like, walls built by stacking stone without mortar, relying on the weight and fit of the material alone. These particular walls are not dramatic or tall, but their arrangement tells a story about how the land here was once divided, worked, and enclosed.

The field system, documented by Liversage in 1968, represents what appears to be a sequence of boundaries that served two purposes: defining the extent of the churchyard around St Begnet's, and marking off land under active cultivation in the early medieval period. The walls and banks run to the north, south, and east of the church, suggesting the whole north-western corner of the island was organised and productive long before the thirteenth century, when the cultivation boundaries seem to have gone out of use. The relationship between the churchyard enclosure and the agricultural boundaries points to a small but functioning community that managed both its sacred and its working land with some care.

Dalkey Island is accessible by short boat trip from Coliemore Harbour in Dalkey village, with local operators running seasonal services. The island is uninhabited and unmanaged in any formal heritage sense, so visitors explore at their own pace. The field system is subtle rather than dramatic; low banks can be difficult to distinguish from natural ground irregularities, especially in summer when vegetation is high. The best time to spot earthworks and low stone features is late autumn or winter, when the grass is short and the low angle of light throws even gentle undulations into relief. Walking north-west from the pier towards St Begnet's Church, it is worth slowing down to read the ground rather than the ruin.