This rectangular tower, measuring roughly 11 metres long by 8.4 metres wide, was already an established stronghold by 1574, when records show it belonged to one ‘Moyler McRichard’. Though time has not been kind to the structure, with the south wall having largely collapsed save for a small section at the southeast corner, the tower still rises three storeys high, offering glimpses into its defensive past.

The castle’s original entrance was positioned towards the western end of the now collapsed south wall, leading into a small lobby complete with a murder hole above; a grim reminder of the building’s defensive purpose. From here, visitors would have encountered a guard room to the west, whilst to the east, an intramural stairway connected to spiral stairs in the southeast angle, though most of these have since crumbled away. The first and second floors housed the main chambers, with smaller subsidiary rooms to the south that featured stone vaulting, now largely collapsed. An intact stone vault still separates the first and second floors, and you can spot a fireplace built into the north wall of the first floor. The windows, consisting of rectangular slits and single lights topped with elegant ogee heads, would have provided both light and defensive positions for the castle’s inhabitants.

The tower itself occupies the northwest section of a flat-topped rectangular platform, measuring approximately 15.2 by 14.6 metres and defined by a visible scarp. Extending south from the tower’s southwest corner, you can still trace the remnants of what appears to be a bawn wall running for about 11 metres; these defensive walls once enclosed a courtyard area typical of Irish tower houses. Despite its ruined state, the castle at An Tamhnach Mhór remains an evocative monument to medieval Irish life, standing as a testament to the turbulent history of North Galway and the families who once called these stone walls home.