This earthwork fortification consists of a roughly circular mound, measuring about 30 metres across at its base and tapering to 10 metres at the summit, rising 4 to 5 metres above the surrounding landscape. The motte still shows traces of its defensive fosse, a water-filled ditch up to 3 metres wide, along with remnants of an outer bank that once provided additional protection. A hollow depression marks the top where a wooden tower likely once stood, though the southern side has lost its topsoil over the centuries.

The western side of the site reveals what archaeologists believe to be the bailey; a raised rectangular area measuring 30 by 35 metres where the castle’s living quarters, stables, and workshops would have stood. Though time has worn down the defining scarps, this enclosed courtyard area remains visible as a distinct feature of the landscape. The castle’s strategic position becomes clear when you consider its neighbours: a medieval church stands to the north, whilst a poorly preserved tower house lies to the east, suggesting this spot held military and administrative importance for centuries.

First documented in historical sources dating back to 1875, with further scholarly attention in the 1930s and 1970s, Rathlihen’s motte and bailey represents a typical Norman stronghold of the type built across Ireland following the Anglo-Norman invasion of the 12th century. The site has been protected under a preservation order since 1986, recognising its significance as part of Ireland’s archaeological heritage. These earthwork castles, whilst less dramatic than their stone successors, played a crucial role in establishing Norman control over newly conquered territories.