No carved details survive, no enclosing graveyard, no trace of burials. What remains is essentially a footprint, roughly eight and a half metres east to west and four and a half metres north to south, pressed into the ground like an outline of something that quietly gave up.

The building served as the private chapel attached to Castletown tower house, a fortified residence that still stands about 165 metres to the north-west. Estate chapels of this kind were common adjuncts to tower houses, the fortified stone residences that dominated the Irish countryside from the later medieval period through to the seventeenth century; they allowed a household to observe religious obligations without travelling to a parish church. A writer named Synnott, recording local details around 1680, noted the existence of a chapel at Castletown, which places the building within living memory of whatever period saw its decline. By 1839, when the Ordnance Survey produced its first detailed six-inch mapping of Ireland, the structure was already described as a ruin, suggesting the collapse happened somewhere in the century or so between Synnott's account and the surveyors' arrival.