But beneath the grass, a geophysical survey has revealed something considerably older: a dense, largely invisible landscape of ditches, pits, and enclosure boundaries that the eye cannot read from the surface but that instruments can detect with some precision. The survey found that the ecclesiastical enclosure at the site, roughly 162 metres in diameter, pushes outward into the fields to the north, south, and west of the church and graveyard, its edges long since absorbed into the ordinary fabric of farmland.

The geophysical survey, carried out under Licence 09R165 and reported by Nicholls in 2009, identified a sub-rectangular network of ditches to the south of the church, running further southward until they meet the boundary of the ecclesiastical enclosure itself. An ecclesiastical enclosure of this kind is essentially the original boundary ditch or bank that defined the territory of an early Irish monastic or church settlement, often circular or roughly oval in plan. The survey suggests that what lies beneath the fields represents settlement activity contemporary with the earliest phases of St Doolagh's, which then shifted and adapted across successive centuries, right through to the nineteenth century. A partial match with boundary alignments shown on the first edition Ordnance Survey six-inch map, produced in the 1830s and 1840s, indicates that some of these ancient lines continued to shape land use long after their original purpose had been forgotten. Scattered among the ditch remains are circular pits and features between one and a half and four metres in diameter, which may represent kilns or other industrial deposits, though their precise function remains uncertain.

St Doolagh's is located near Balgriffin, just off the Malahide Road north of Dublin city. The medieval church itself is freely visible from the road and the surrounding area is accessible, though visitors should be aware that the buried field system is detectable only through the kind of specialist survey described above rather than anything visible at ground level. The site rewards a slow, attentive visit rather than a quick one; the church and its associated structures are the obvious draw, but knowing that the fields around you contain the ghost of an early medieval settlement, its ditches still legible underground, adds a different kind of weight to the ordinary-looking landscape.