Though nothing remains visible above ground today, this site once hosted what appears to have been a formidable tower house. Historical records from 1599 paint a vivid picture of the structure in its prime, describing it as ‘a square castle and a great bawne with a good dytche rounde abowte it’; essentially a fortified tower with a defensive courtyard enclosed by walls and surrounded by a substantial ditch.

The castle’s complete disappearance from the landscape speaks to the turbulent history of Irish fortifications during and after the plantation period. Tower houses like Niselrath were common throughout Ireland from the 15th to 17th centuries, serving as both defensive structures and symbols of authority for Anglo-Norman and Gaelic lords alike. These compact vertical castles typically featured thick walls, narrow windows, and multiple floors accessed by spiral staircases, all designed to withstand siege whilst providing comfortable accommodation for the lord’s family.

Today, visitors to the Castle Field will find no stone or earthwork to mark where Niselrath once stood, yet the site remains significant to our understanding of Louth’s medieval landscape. The detailed description from 1599, preserved through historical surveys and archaeological inventories, provides valuable insight into the defensive architecture of the period. The mention of a bawn, a fortified enclosure typical of Irish castles, suggests this was more than a simple tower; it was a complete defensive complex designed to protect both people and livestock during times of conflict.