The Poulaphouca Reservoir, created in the 1940s to serve Dublin's water and electricity needs, flooded the valley of the Liffey and submerged entire townlands. What it left behind at Burgage More is a place caught between two kinds of erasure: first the slow abandonment of a medieval settlement, and then the creeping waterline that finished the job.

The church here was once part of a functioning borough, Burgage More, whose lands belonged to the bishops of Glendalough as far back as the twelfth century. Glendalough, the famous monastic site in the Wicklow Mountains, held ecclesiastical influence across a wide stretch of the region, and this small church near the confluence of the Liffey and the King's River would have served the community that grew up around that episcopal ownership. What survives today is modest: the low foundations of a rectangular structure, roughly eleven metres east to west and nine metres north to south, with walls standing barely above ground level. Around it lies a graveyard of roughly 55 by 70 metres, bounded by a modern wall and, on its eastern and western edges, by two old roads that predate the reservoir entirely. The graveyard has suffered badly from the water, and no grave-markers remain visible. A font recorded here by Reynolds in 1973 has since disappeared. Two high crosses, or the remains of them, once stood on the site but were relocated to a newer graveyard about 800 metres to the north. A holy well was also associated with the place, and a tower house, the fortified residential structure typical of late medieval Ireland, sits close by to the south.

The spit of land is accessible when water levels in the reservoir are low enough to expose it fully, which tends to depend on seasonal conditions and water management. The foundations are slight and require some patience to read as a building, but the setting, with old roads leading to a waterlogged graveyard on a peninsula that was once an inland junction of two rivers, gives the place a geography that rewards a slow walk rather than a quick glance.