Originally a manor belonging to the Bishop of Limerick from the early 13th century, it had passed into the hands of the powerful Desmond family by the 1300s. The rectangular two-storey structure, measuring roughly 17.6 metres east to west and 8.15 metres north to south, showcases the typical defensive architecture of medieval Ireland with its thick limestone walls, prominent base batter, and chamfered corners that taper elegantly down the fortified face.

The castle’s most intriguing feature is its vaulted ground floor, though this wasn’t part of the original design. Two parallel wicker-centred vaults, running east to west and supported by a central arcade of six open bays, were inserted during the 15th or 16th century, transforming what was likely an open hall into a more secure storage space. The western end of the ground floor remains unvaulted, separated by a cross-wall containing narrow mural stairs; a practical arrangement that provided internal access between floors whilst maintaining the building’s defensive integrity. Seven original window embrasures pierce the ground floor walls, though most have been heavily robbed of their stone surrounds over the centuries, leaving only the western window with its tall, narrow, flat-headed light intact, albeit now blocked.

The first floor, which would have served as the main living quarters, tells its own story through ruined window embrasures and doorways. A semi-circular arched doorway in the north wall, built from plain limestone blocks, once provided the principal entrance, whilst opposite in the south wall, the remains of a drawbar socket hint at additional security measures. The western wall contains two particularly interesting features: a small mural chamber housing a garderobe, and a steep stairway leading to what was once an attic floor, supported by stone corbels whose bases formed elegant engaged columns. Today, partially cloaked in ivy and standing within the same enclosure as the ruined parish church of Tomdeely, this castle remains a tangible link to the complex web of ecclesiastical and noble power that shaped medieval Limerick.