Built by the O’Flaherty clan, who dominated the region west of Lough Corrib for centuries, this fortification served as both a defensive stronghold and a symbol of their authority over Connemara. The O’Flahertys, known as Lords of Iar Connacht, controlled this territory from their various castles scattered across the rugged landscape, with Rinville Castle strategically positioned to oversee Galway Bay and protect their lands from seaborne threats.

The castle’s architecture reflects the typical Irish tower house design of the late medieval period, featuring thick stone walls, narrow windows, and multiple floors that once housed the clan’s warriors, servants, and nobility. During its heyday, the structure would have been the centre of local life; a place where rents were collected, justice was dispensed, and alliances were forged through marriages and feasts. The O’Flahertys’ reign here lasted until the Cromwellian conquest of the 1650s, when their power was systematically dismantled and their lands redistributed to English settlers.

Today, the castle ruins stand as a weathered monument to a vanished way of life, its stones bearing witness to centuries of Irish history. Visitors can still trace the outline of the great hall, climb the worn spiral staircase, and imagine the bustling medieval settlement that once surrounded these walls. The site offers a tangible connection to the Gaelic lords who ruled this corner of Ireland long before the plantation era transformed the social and political landscape of the country forever.