The earthwork in question sits on the western bank of the River Suck, close to an ancient ford and bridging point, the kind of crossing that would have made the location strategically significant for centuries before anyone thought to build a church there.

Local tradition, supported by annalistic sources, holds that the site is that of Dún Leodha, a fortified enclosure built in 1124 by Toirdhealbhach O'Connor, King of Connacht, one of the most powerful rulers in twelfth-century Ireland. The present church was constructed between 1852 and 1857, replacing an earlier chapel on the same ground. Writing in 1837, the scholar John O'Donovan recorded that parts of the ramparts could still be traced within and around the chapel enclosure, and he noted, drawing on oral accounts, that before the earlier chapel was built, the site had presented the appearance of a truncated cone, the kind of mounded earthen form typical of early medieval fortifications. The discovery of oak coffins during that levelling work suggests the site had also served, at some point, as a burial ground, though quite when or for whom is not recorded.

What remains today is largely subsumed beneath the church and its surrounds, making this less a place to visit for visible archaeology than for the quiet awareness that a twelfth-century royal stronghold once occupied ground that now sees Sunday Mass. The river crossing nearby, still traceable, gives some sense of why this particular bend in the Suck mattered so much, and for so long.