This defensive wall, measuring 1.3 metres thick, creates a fortified enclosure of 47 metres north to south and 33 metres east to west. The castle represents a fascinating example of late 16th or early 17th century plantation architecture, likely built during the Tudor or Stuart colonisation efforts in Ireland.

The most intriguing surviving feature is the oval-shaped bastion at the northeast corner, measuring 4.6 by 8.6 metres internally. This bastion contains two vertical garderobe chutes positioned opposite each other in the north and south walls, right where they meet the main bawn wall. The northern chute, with its arched opening measuring 0.7 by 1.5 metres, once emptied into what was originally a moat surrounding the entire structure. Today, only the northwest section of this flat-bottomed moat remains visible, stretching 6.5 metres wide and 0.75 metres deep. While the other three corner bastions have been lost to time, an unusual square foundation projects from the southern end of the eastern wall, likely the base of a defensive tower.

The design bears striking similarities to the Powder Mills in Ballincollig, County Cork, where towers along the bawn wall served as living quarters rather than purely defensive structures. The raised interior of Moyally’s bawn shows faint traces of rectangular structures built against the inner walls, suggesting this castle once housed a small community within its protective embrace. These plantation castles served dual purposes; they were both fortified residences for English and Scottish settlers and symbols of the new order being imposed on the Irish landscape during this turbulent period of colonisation.