What gives this particular site its quiet interest is the layering beneath it: the Protestant church, now ruined, was built directly on top of a medieval predecessor, meaning that a single footprint in the landscape contains centuries of continuous religious use, one building absorbed into the ground and another raised in its place, each generation making use of what came before.

The scholar and antiquary Thomas Johnson Westropp, who systematically documented early ecclesiastical and historical sites across Munster in the early twentieth century, recorded the place-name history of Drehidtarsna in some detail. The earliest reference he found dates to 1201, when the settlement appears as Drochetarsna. By 1223, a certain G. de Mareys, a figure whose name suggests Anglo-Norman connections, was recorded doing homage to Bishop Hubert for the lands of Drethenarsna, or Drethenetarsna, as it was alternatively spelled in that document, the Black Book of Limerick. The name shifts again to Drohidtarsna in 1418 and settles closer to its modern form, Drehidtarsna, by 1615. Westropp noted plainly that the Church of Ireland building occupied the old site, a brief observation that nonetheless confirms the continuity. The parish itself sat within the historic territories of Coshmagh and Upper Connello, two of the medieval administrative divisions that once carved up County Limerick.

The site is a modest one, and those approaching it should not expect an elaborate ruin. Aerial photographs taken in March 2006 as part of the Archaeological Survey of Ireland give a clearer sense of its form than is immediately obvious from ground level, where surrounding vegetation and the general flatness of the terrain can make it easy to walk past without registering what is there. The ruins are the kind that reward a slow look rather than a quick glance; the interest lies not in dramatic standing walls but in the logic of the place, the fact that people chose this particular spot, named it, argued over it, and built on it again and again across more than four centuries of recorded history.