To the north of the main enclosure are the remains of a pair of parallel embankments. While almost entirely destroyed, these may once have been significant features. The distance between the two embankments is c. 65 m and they appear to be carefully located to cut off the lowest approach to the summit of the hill. There are possible traces of enclosure to the southwest of the Hill also, giving some suggestion that the entire hilltop might once have been enclosed.
The presence of such an enclosure would suggest that the origins of Tlachtga lie earlier than the early medieval period to which ringforts (although Tlachtga is not in any sense a typical ringfort…) generally belong, perhaps as a Bronze Age hillfort or hilltop enclosure. If the entire hilltop were enclosed the overall size of such an enclosure would have to be truly massive – nearly 900 m along its long axis (roughly three times the size of Rathgall, Co. Wicklow and larger even than Brusselstown Ring, Co. Wicklow) by 550 m across.
There are suggestions of an enclosing feature even further to the north, where a ditch running parallel to the ‘inner’ enclosures follows the line of an old field boundary. In the 6″ and 25″ OSI mapping a standing stone (St Lawrence’s Stone) is marked on this boundary, potentially marking the northern limit of the site. Local folklore suggests that the St Lawrence’s Stone was removed mistakenly to the churchyard of St Laurence, Rathmore (a large stone certainly stands within the churchyard).
Conor Newman (2005) draws attention to two other standing stones to the east of the hill, while a possible third may have lain in Rathcarran townland, again to the east.
Newman, C. 2005. Re-composing the archaeological landscape of Tara. In Bhreatnach, E. (ed.) The Kingship and Landscape of Tara. Four Courts, Dublin.