The site measures approximately 13.9 metres from north-northeast to south-southwest and 12.1 metres from west-northwest to east-southeast. What survives today are the remnants of substantial walls on the northern and western sides, originally between 1.25 and 1.45 metres thick, though centuries of accumulated earth have transformed them into broader banks ranging from 3.1 to 3.7 metres in width and standing just 0.3 to 0.6 metres high.

The eastern and southern boundaries tell a different story; here, the enclosure meets the edge of a low sea cliff that drops steeply, though not vertically, to the waters below. It seems likely that whatever walls once stood on these seaward sides have long since succumbed to coastal erosion, though a small section of the bank remains visible on the east-southeast side, hinting at the site’s original form. The entire structure sits on a gentle slope leading down to the sea, surrounded by decent pasture land that has likely been grazed for generations.

This description comes from the Archaeological Survey of County Donegal, a comprehensive catalogue compiled by Brian Lacey and his team in 1983 that documents the county’s archaeological heritage from the Mesolithic period through to the 17th century. Like many such sites along Ireland’s Atlantic coast, the Largysillagh enclosure raises more questions than it answers; its age, function, and the people who built it remain mysteries, preserved only in these wind-worn stones and earthen banks that continue their slow dialogue with the sea.