This late 15th or 16th-century circular tower house, built from granite rubble, rises four storeys from a rocky outcrop that’s still visible inside at ground level. The Mountgarret family held the castle until 1621, but it was confiscated during the Cromwellian conquest in 1653. With an external diameter of 10.8 metres and a rectangular garderobe turret projecting from the northwest side, the tower represents a formidable example of late medieval defensive architecture.

The castle’s defensive features reveal the turbulent times in which it was built. Three machicolations at parapet level; one positioned above the main eastern entrance and two others in the southeast and southwest; allowed defenders to drop projectiles on attackers below. The original pointed doorway was protected by a yett (iron gate), evidenced by the surviving yett-hole in the southern jamb, whilst a murder hole in the entrance lobby provided additional security. Throughout the tower, numerous gun loops of various designs, including rectangular, cross-shaped and equal-armed variations, pierce the walls alongside the window embrasures, allowing defenders to cover multiple angles of approach.

Inside, the tower’s layout follows the typical pattern of Irish tower houses, with each floor serving distinct purposes. The vaulted ground floor chamber, remarkably preserving its wicker centring marks, features large embrasures housing defensive loops and storage recesses. A spiral staircase in the southeast wall connects all levels, whilst the upper floors, which originally had timber flooring, contained more comfortable accommodation. The first and second floors each include wall cupboards, windows and access to the garderobe facilities in the projecting turret. The second and third floors were warmed by fireplaces; one in the northwest wall and another in the northeast; marking these as the principal living chambers. The third floor once boasted a round-headed three-light window according to historical records from 1905, though this has since been damaged. A narrow mural stair from this level leads to the partially surviving parapet walk, where the defensive machicolations show interesting variations in their construction methods.