The rectangular walled area, measuring 44 metres by 54 metres, sits near Morgans House, with the medieval church and graveyard lying about 1.2 kilometres to the southeast. Whilst the outer walls are of relatively recent construction, built to the standard two-foot thickness typical of the period, they incorporate something far older and more intriguing along the northeastern side.

This earlier structure consists of a 7.5-metre stretch of wall, considerably thicker at 1.35 metres, with a rectangular projection at its southeastern end. Inside this projection, a small lintelled chamber reveals its original purpose; a garderobe opening at one end and a wall press suggest this was once part of a larger residential complex. The presence of two garderobe shafts in the outer wall confirms that this projection once served upper floors, now lost. Archaeological analysis by Donnelly suggests this could have functioned as a defensive flanker, providing covering fire along the northeastern wall face, whilst its architectural character points to late medieval origins.

Historical records paint a picture of Morgans as a significant fortification through the centuries. The 1658 Down Survey map depicts it as a tower house structure, and by 1587, Sir John of Desmond held what was described as a ruinous castle here. The site’s strategic importance continued into the early 17th century when, following the attainder of John Fitzgerald, it was granted to Richard Boyle in 1603, complete with “an old stone Castle and bawne”. Earlier references stretch back to 1201, when it was known as Disuirt Murdewar, later becoming Disert Muirdeabhair or Morgans by 1410, suggesting a long and complex history of occupation and fortification at this Shannon estuary location.