This flat-topped earthwork, measuring roughly 29 metres across at its base and 11 metres at its summit, stands about 4 metres high; a modest but significant remnant of Norman fortification in Ireland. The motte would have originally supported a wooden tower or palisade, serving as both a defensive stronghold and a symbol of Norman authority in the region following their arrival in the 12th century.

Time and human activity have taken their toll on this ancient fortification. A modern trackway has carved into the northern base of the mound, whilst construction work and subsequent demolition have disturbed the eastern side. The western portion has also seen some removal of material, leaving only the southern face relatively intact and true to its original form. Despite careful archaeological surveys conducted in the 1980s and early 1990s, no evidence has been found of a bailey, the enclosed courtyard that typically accompanied such structures, nor of any defensive ditch or fosse that might have surrounded the motte.

What remains today is a somewhat battered but still recognisable example of Norman military architecture, one of many such earthworks scattered across the Irish landscape. These mottes, often built hastily using local labour and materials, represented the first phase of Norman castle building in Ireland before more permanent stone structures became the norm. The Mayne motte, though lacking the drama of larger sites, offers a tangible connection to the tumultuous period when Norman lords were establishing their foothold in medieval Louth.