Sir Thomas Ridgeway constructed the original fortress between 1606 and 1612, strategically positioning it amongst woods and natural springs that provided both defensive advantages and the convenience of creating fish ponds nearby. The castle’s location was so well chosen that when Confederate forces seized it in 1642, contemporary accounts described it as being “seated among woods in a place soe watered with springs” that the Earl had established multiple fish ponds, whilst fortifying the structure with a strong wall complete with turrets and flankers. The nearby iron mill kept many workers employed, helping the planted town to thrive.

The castle’s military significance proved to be its downfall during the turbulent 1640s. After Preston’s Confederate forces captured it in 1642, the Cromwellian army later besieged the fortress, with Fairfax reportedly battering it from a neighbouring hill near Heywood Demesne whilst the garrison mounted a brave defence. The destruction was so complete that when the Dunne family constructed a replacement castle on the site in 1680, local tradition maintains it was never actually inhabited. Nineteenth century photographs reveal the original structure once soared five storeys high, though today only fragments remain to hint at its former grandeur.

What survives of Ballinakill Castle includes the north gable wall, stretching approximately 5.3 metres and standing three storeys tall, built from roughly coursed pink shaley stone with dressed limestone quoins. Defensive gun loops are still visible on the ground and first floors, whilst a large window pierces the second floor. Northwest of the tower house, visitors can spot what may have been the original arched gateway into the bawn; remnants of the bawn wall itself remain attached to the external face of the west wall. Just 233 metres northwest lies All Saints church and graveyard, with the area’s ecclesiastical heritage reflected in old place names like Kilcroannen, meaning the Church of St. Cronan, which appear on Down Survey maps from the 17th century.