What makes it quietly puzzling is what it never contained: when archaeologists excavated the site in 1972, they found no evidence of occupation at any period. No hearths, no post-holes, no domestic debris. The enclosure, measuring roughly 70 metres on its longer axis, was built apparently not to shelter people but to define or delimit something else entirely, most likely a sacred precinct within the broader monastic landscape of the island.

The earthwork is part of a wider field system connected to the early medieval monastery on Inis Cealtra, a community whose origins are associated with the sixth century. The enclosure itself, a bank and fosse construction, where a fosse is simply a ditch dug to reinforce the bank thrown up beside it, takes a slightly different form on each side. The eastern boundary is a single straight bank, while the arc running from south through northwest to northeast is more elaborately constructed, with an external ditch and a further outer bank beyond it. A charcoal sample taken from the straight eastern fosse during the 1972 excavation was radiocarbon dated to between approximately 905 and 1023 AD, placing the construction firmly in the later part of the early medieval period. A penitential station associated with the site, a place where pilgrims would traditionally pray or perform acts of devotion on a prescribed circuit, continues to be visited, suggesting that the enclosure's role as a structuring presence in the religious life of the island has not entirely dissolved.