This impressive medieval fortification consists of a flat-topped mound built from earth and stone, measuring 16 metres across at its summit and expanding to 45 metres at its base. The structure rises between 5 and 8 metres high, with the southern side notably taller than the northern. A defensive ditch, or fosse, surrounds the mound with a base width of 4 to 5 metres, and faint traces of an outer bank can still be detected running from the southeast to the west-northwest.

Archaeological evidence suggests this motte formed part of a larger defensive complex. A bailey, the enclosed courtyard typical of Norman fortifications, likely extended along the ridge to the north-northwest, occupying the 40-metre stretch between the motte and the nearby graveyard church. The remains of a castle structure crown the motte’s summit, whilst an ancient field system lies immediately to the east, indicating the site’s long history of occupation and use.

This type of motte-and-bailey fortification was introduced to Ireland by the Anglo-Normans in the late 12th century, serving as both military strongholds and administrative centres. The Milltown example demonstrates the typical design of these earthworks: a raised mound providing a defensive advantage, surrounded by a ditch for additional protection, and connected to a lower enclosed area where daily activities would have taken place. The grass-covered mound today offers little hint of the timber palisades and buildings that would have once topped it, but its substantial earthworks remain an enduring testament to medieval engineering and the strategic importance of this Meath location.