Church Lane bends gently as it runs south of High Street; Vicar Street and Shop Street carry the faintest arc in their axes. These are not the accidents of medieval town planning. They are, or may be, the ghost of a very large early ecclesiastical enclosure, its original boundary absorbed so thoroughly into the urban fabric that the town itself has become the record.

The visible remains sit on the south side of High Street: a raised, roughly D-shaped graveyard with a ruined church at its eastern end. The graveyard sits elevated above the surrounding ground, which is itself a common sign of long, continuous use and accumulated burial deposits. The curving south-east wall of the graveyard almost certainly traces part of what was once a large, possibly semicircular enclosure measuring more than a hundred metres east to west. The enclosure would originally have looked out over a marshy area to the north-west, suggesting it was sited with some deliberateness on slightly higher, drier ground. Associated with the site is a cross-slab, a flat stone carved with a cross, of the kind commonly found at early medieval Irish ecclesiastical sites. The enclosure lies around 150 metres north-east of St Mary's Cathedral, itself a site of considerable antiquity, which gives some sense of how substantial and spatially organised early Christian Tuam must have been. A further, larger concentric outer enclosure has been proposed, based on the curving street lines of Vicar Street and Shop Street, though this remains speculative rather than confirmed.

For those who know what to look for, the curve of Church Lane as it follows the south section of the old graveyard wall is the clearest physical trace. The raised ground of the graveyard is visible from the street, and the ruined church at the eastern end is accessible within it. The cross-slab associated with the site adds a tangible early medieval presence to what might otherwise read simply as an old town-centre burial ground.