Its outline survives only in crop marks, visible from the air when conditions are right, and in a single aerial photograph that captures most of its extent. What was once, by all indications, a substantial and wealthy early Christian settlement has left almost no physical trace on the landscape.

The place name itself offers a clue to the site's age. Rattoo derives from Rath Tuaidh, or more fully Rath maigi tuaidh, meaning the fort of the northern plain, suggesting a pre-ecclesiastical identity that was later absorbed into Christian use. Scholars Gwynn and Hadcock proposed in 1970 that the foundation may date to the early sixth century, with a possible association with a Bishop Lughach, though documentary evidence is thin. By the thirteenth century the site was significant enough for the Anglo-Normans to establish a borough here, and the survival of a round tower, the tall slender stone structures built by early Irish monasteries, points to a community of considerable means. Rattoo was also linked to the nearby ecclesiastical site at Dysert by an ancient roadway known as a togher, a timber or brushwood track laid across boggy ground. The Ordnance Survey Name Books of 1841 recorded this route as the White Horse Ridge, running from the old church at Dysert through the bog to Rattoo. When William Morrison visited in 1832, the round tower still stood on a circular earthen terrace with a causeway stretching roughly 38.7 metres to the east. Around 1880, Wilson Gunn of Rattoo House drained and planted the surrounding land, and the causeway disappeared with it. By then, the enclosure itself had already been gone from view for some time, legible only to those looking down from above.