This medieval earthwork forms a neat rectangle measuring roughly 35 metres east to west and 47 metres north to south. The site’s defences consist of three distinct features: an inner bank standing nearly 2.5 metres high on its outer face, a broad flat-bottomed ditch about 6 metres wide and 3 metres deep, and an outer bank that rises 1.75 metres above the surrounding pasture. The outer bank appears particularly well-preserved along the western and northern sides.

The interior of the enclosure slopes gently northward, following the natural contour of the land. A clever bit of medieval engineering can be seen in the southwest corner, where a purposely cut channel, or leat, directs water through the outer bank to fill the defensive ditch. This would have kept the moat supplied with water, making it a more formidable barrier against unwanted visitors. The southeast corner shows signs of later disturbance, with the ditch filled in at this point, though the rest of the earthwork remains remarkably intact.

These moated sites are characteristic of Anglo-Norman settlement in Ireland, typically dating from the 13th to 14th centuries. They served as fortified farmsteads for colonising families, offering protection whilst managing agricultural estates. The Tiermoyle example, documented in the Archaeological Inventory of County Tipperary, represents one of many such sites scattered across North Tipperary’s landscape, each telling a story of medieval life when security and status were literally written into the earth.