The tower, measuring 9.8 metres north to south and 10.5 metres east to west, is all that remains of what was once a more impressive fortification. A 1600 illustration of its siege shows it as a five-storey tower anchored to the southwest corner of a rectangular bawn, though today it reaches only three storeys and the protective bawn wall has vanished without trace. Dense ivy now masks most of the upper exterior walls, lending the ruins an air of romantic decay.

The tower’s ground floor, accessed through one of two external doorways in the north wall, contains a vaulted chamber measuring 6.5 by 4.9 metres. Windows pierce the south and west walls, each set within deep, square embrasures covered by segmental vaults; though time has claimed most of the window lights themselves. A spiral staircase once rose through the northeast corner, providing access to the upper floors and, according to that 1600 drawing, originally extended to a cap house that opened onto the wall walk. The first floor chamber features similar window arrangements and includes a garderobe tucked into a mural chamber on the eastern side, whilst the second floor sits beneath a partially collapsed barrel vault.

This site has witnessed considerable history since the Knights of Glin established a castle here in the 13th century, though nothing visible today predates the 15th century. Sir George Carew besieged and captured the castle in 1600, but it was later returned to the Knights of Glin and repaired, as evidenced by an inscribed plaque dated 1615 that originally graced a fireplace here but now resides in the gateway at Glin Castle country house. By the late 18th century, illustrations show the tower had already been reduced to its current height, standing alone as a testament to the turbulent centuries it has weathered.