The site sits on a pronounced northeast-facing slope at Ballinacor, though visitors today will find no visible traces of the castle that allegedly stood here. Without any physical remains at ground level or supporting archaeological evidence, the location exists primarily in local memory and oral history.

Phelim McFeagh O’Byrne was a significant figure in Irish resistance during the early 1600s, leading guerrilla campaigns against English forces from his mountain strongholds throughout Wicklow. His name appears frequently in contemporary accounts as a formidable opponent who used the rugged Wicklow terrain to his advantage, launching raids and then melting back into the mountains. The O’Byrnes had long controlled this region, and Phelim McFeagh represented one of the last gasps of Gaelic lordship in the area before the final imposition of English authority.

While the exact location of his castle remains unverified by archaeology, the association of this particular spot with such a notable historical figure speaks to the enduring power of local tradition in preserving memory. The Avonbeg valley below would have provided an excellent vantage point for monitoring movement through the glen, making it a strategically sensible location for a defensive structure. Whether stone foundations lie buried beneath the soil or the “castle” was perhaps a more temporary fortification of timber and earth, the site continues to hold its place in the landscape of Wicklow’s turbulent past.