According to the OS Letters from 1836 and local historian O’Rorke’s account from 1890, this fortification was built by the MacFirbis family in 1560. However, Wood-Martin’s 1882 records present a slightly different narrative, agreeing with the construction date but claiming the O’Dowds as the original builders. Following the turbulent events of 1641, the O’Dowds apparently fortified the castle further before it eventually passed into the hands of the Wood family.

Today, visitors to Lackan will find modest but intriguing remains that hint at the castle’s former presence. A rubble mound measuring roughly 10.5 metres east to west and 6 metres north to south rises to a maximum height of 1.4 metres, now bisected by a modern field boundary wall. The most substantial surviving features include visible wall bases along the southern side, standing about 0.6 metres high, and an eastern wall section that stretches for 6 metres and reaches 1.1 metres in height with a thickness of 0.8 metres. A low earthen bank running east to west may mark where the northern wall once stood, whilst a narrow break in the southern wall, less than a metre wide, likely indicates the castle’s original entrance.

These weathered ruins, compiled and documented by Patrick F. O’Donovan in 2011, offer a tangible connection to the contested histories of Connacht’s noble families. Whilst the castle’s precise origins remain debated amongst historical sources, its strategic position overlooking Killala Bay and its role in the upheavals of the 1640s mark it as a significant, if understated, piece of Ireland’s fortified heritage.