That uncertainty is precisely what makes the site interesting. The area known locally as Abbey Field, occupying the eastern half of the castle lawn and sitting in the flood plain of the River Blackwater, is the proposed location of the long-vanished Litter parish church, yet the physical evidence for it has proved stubbornly elusive.

The case for Abbey Field rests largely on the work of O'Shea, writing in 1947, who placed the church here and described what he saw at the south-east corner of the site: the remains of a building with one wall four feet thick, eight feet high, and roughly ten feet long, pierced by a narrow slit window. It is a specific enough description to carry some weight. Slit windows of that kind are a common feature of medieval ecclesiastical and defensive masonry in Ireland, admitting light while offering little else. The difficulty is that subsequent investigation found ruined walls in the area but nothing that corresponded to O'Shea's account. A competing theory, put forward by Power in 1932, places the Litter church not here at all but at a deserted settlement at Ballynoe. Both arguments remain unresolved, leaving the church in a kind of historical suspension, claimed by two locations and confirmed by neither.

The site lies in woodland at the base of a north-facing slope on the demesne of Cregg Castle, which is private land. Access would depend on the usual courtesies that apply to estate grounds. What a visitor might actually find is difficult to say with confidence, given that the masonry O'Shea described could not later be matched. That gap between a detailed Victorian-era account and the physical reality on the ground is, in its own way, as telling as any surviving wall.