This substantial earthwork, with its steep grass-covered sides and conical profile, marks the site of a former Anglo-Norman borough about 200 metres south of the Hartwell River, a small tributary that flows westward into the Liffey. Though the first written reference to a castle here dates only to the 16th century, historians believe the motte was constructed in the late 12th or 13th century during the Anglo-Norman expansion into Ireland.

The monument’s defensive architecture remains remarkably intact despite centuries of wear. The main mound measures 46 metres across its base from north to south, narrowing to a summit platform of 17 metres east to west and 13 metres north to south. This central feature is surrounded by an elaborate system of earthworks: an inner fosse 7.5 metres wide encircles the motte, followed by a broad outer bank that varies from 12 metres wide on the western side to 18 metres on the east, with heights ranging from 3 to 7 metres. Beyond this lies a second, much broader outer fosse, originally 17 metres wide, though modern roads and laneways have overlain portions of it, and quarrying has removed sections along the northern edge.

The site has a complex history of use and reuse spanning centuries. Immediately to the south lie a medieval church site and graveyard, testament to the settlement’s religious significance. Unfortunately, extensive gravel extraction for road construction from the late 19th century onwards severely damaged the probable bailey area north of the motte; by 1955, observers noted it had been quarried to within a few yards of the main mound. These destructive activities did yield some archaeological discoveries, including human burials and an Early Historic bronze bracelet found in the vicinity. The monument has been protected under a preservation order since 1956, helping to safeguard what remains of this significant piece of Anglo-Norman heritage.