By that time, most of the structure lay in ruins, with only the choir or chancel still roofed and serving as the local Protestant church. The surviving portion measured 53 feet in length, whilst the unroofed nave stretched 50 feet long by 30 feet wide. Even more intriguingly, the surveyors noted the remnants of a castle attached to the church’s western end, though only its eastern wall and fragments of the north and south walls remained standing at about 30 feet high.

The castle itself has a rather mysterious history. Known as ‘Castell fferson’ in 1591, it appears to have vanished entirely by the late 20th century, with historians noting that no trace survived by 1989, despite being marked on old Ordnance Survey maps south-west of the church. The 19th-century historian Lewis even suggested there might have been two castles at Croagh, adding another layer to the site’s enigmatic past.

The lands of Croagh, also known as Moychro or Maynchro, have a documented history stretching back to 1289 when Hugh Purcell granted woods and turf rights to the local bishop. The Purcell family maintained their connection to Croagh for centuries, with the estate passing through various branches of the family amid the turbulent politics of medieval and early modern Ireland. Notable figures include Lieutenant Patrick Purcell, who played a significant role as a Confederate leader during the 1641 rebellion and was remembered as both brave and humane. By 1611, Edmund Purcell had been granted permission to establish a manor at Croagh complete with courts Leet and Baron and free warren rights. The estate eventually passed out of Purcell hands, and by 1726 had been settled on Edmund Browne of Ballyslattery in County Clare through a marriage alliance with Jane Westropp.