What makes it quietly telling is what it once was and what it was never quite meant to be: a mass-house, thrown up at the end of the eighteenth century as a place where Catholic worship could continue under the constraints of the Penal Laws, when permanent, purpose-built churches were legally restricted and congregations often gathered in rudimentary structures as a result. It served its community for the better part of a century before being superseded, which makes its survival as a ruin less a coincidence than a record of two distinct eras of Catholic life in Clare.

The building is modest in scale, measuring just over twenty metres east to west and a little over six metres north to south, with walls that still stand to between one and two and a half metres in places, though the north wall has fared worst. Near the east end of that northern wall there is a gap about 1.2 metres wide that was almost certainly a doorway; the presence of a stoup, a small basin for holy water, set into the wall just to the west of it supports that reading. No other openings are now legible in the fabric. What does survive in good condition are the quoins, the large dressed corner stones, measuring roughly 0.8 by 0.4 by 0.3 metres and laid in alternating directions to bind the corners with some structural care. That attention to the corners, set against the otherwise plain and functional construction, suggests a building put up by people working with limited resources but not without craft. The church continued in use as the Roman Catholic parish church until St. Mary's at nearby Roxton was built in 1869, at which point Liscullaun was effectively retired.