A low earthen bank barely a quarter of a metre high, curving through pasture south of Carton Demesne, is not the kind of thing that announces itself. Yet this faint arc in the Kildare landscape is likely all that remains visible of what was once a substantial early ecclesiastical enclosure, roughly 130 metres across, with a formal embanked entrance roadway still partially traceable for some 52 metres running north to south. At the centre sits a small oval graveyard containing the ruins of a medieval church and, once, an ogham stone, those inscribed standing stones carved in an early Irish script used from roughly the fourth century onwards. The whole arrangement, outer enclosure, entrance causeway, and inner sacred zone, follows a pattern well recognised at early Irish monastic sites, where concentric boundaries marked out graduated degrees of sanctity.

The place-name itself carries considerable weight. Gwynn and Hadcock identified this as 'Domhnach-mor-maige-luadat', meaning the great church of Nuadhat's plain, a territory associated with Maynooth. The 'Domhnach' element, from the Latin 'dominicum', a term for a church, is generally understood to signal a foundation with Patrician connections, that is, one associated with the earliest wave of Christianity in Ireland, possibly as far back as the fifth century. Later tradition held that St Erc, a bishop and disciple of the sixth-century St Senan, was associated with the site. The outer enclosure is now poorly preserved, its northern and western arc largely lost, with some of it possibly buried beneath a railway embankment that cuts across the site. A shallow external fosse, a ditch running outside the bank, survives between the eastern and southern stretches, and an internal bank subdivides part of the south-eastern sector, hinting at a more complex original layout than what survives above ground. The graveyard at the centre may itself overlie an earlier inner enclosure, estimated at around 60 metres across, that preceded the present arrangement.