The site commands impressive views across the landscape, its western edge defined by the dramatic cliff face itself whilst the remaining perimeter is marked by the ruins of a semicircular drystone wall. This substantial wall, measuring approximately 2.5 metres in width, would have provided formidable protection for those who lived within its bounds centuries ago.

The internal space of the cashel forms a distinctive D shape, measuring 15 metres from east to west and the same distance from north to south. A gap in the eastern section of the wall, roughly 2.25 metres wide, marks what was likely the original entrance to the fortification. Today, a modern field boundary runs alongside the eastern edge of the site, a reminder of how the landscape continues to evolve around these ancient structures.

This particular cashel exemplifies the defensive settlements that dotted the Irish countryside from early medieval times onwards. Its strategic position on the cliff edge would have offered both natural protection and excellent visibility of approaching visitors or threats. The site was documented in the Archaeological Survey of County Donegal, compiled by Brian Lacey and his team in 1983, which catalogued field antiquities spanning from the Mesolithic Period through to the 17th century. Though now in ruins, the cashel at Carrownaganonagh remains a tangible link to Ireland’s fortified past, when such structures served as both homes and strongholds for local communities.