What is recorded here

Caislen-na-Circe, meaning Castle of the Hen, stands on Castle Island in County Mayo as a ruined limestone tower house built to control local waterways. The O'Malleys likely occupied the island during the late medieval period, using the surrounding water to block attackers while defending the coast. Time and Atlantic weather have reduced much of the structure to rubble, yet enough remains to show why this lonely outpost mattered.

Castle Island is recorded as a islet in County Mayo. Its open map record supplies this location and any linked names or public references.