The site, positioned on a natural promontory on the western side of a north-south stream valley, was originally a de Londres fief from the early days of Anglo-Norman colonisation. From 1355, however, the Meiler family became the primary landholders, and the manor gained alternative names including Ballycarroll and Ballymackarvill. The Civil Survey of 1654-6 records that Nicholas Meyler inherited 730 acres in Duncormick parish, including 40 acres at Duncormick itself, though the survey notes the castle's presence without definitively establishing its ownership at that time.

The castle stood as a tall, narrow tower well into the 19th century, with early accounts describing a doorway positioned close to one corner of the structure. The promontory on which it sits measures approximately 51 metres east to west and 38 metres north to south, rising 4 to 6.5 metres in height. A substantial trench or fosse runs along the southern edge of the promontory; this defensive feature spans 13 to 15 metres wide and plunges 6 to 6.5 metres deep, extending westward for about 100 metres to meet a public road, with a slight northward curve at its western end. Whether this impressive earthwork is entirely man-made or enhanced from a natural feature remains uncertain.

The castle's strategic importance becomes clearer when considering its relationship to other medieval structures in the vicinity. A motte and bailey fortification lies roughly 120 metres to the northeast, whilst the parish church stands about 210 metres east-northeast, across the river. Today, whilst the castle itself has vanished, the promontory remains partially occupied by a modern house. The Meiler family's connection to the site ended dramatically during the Cromwellian period; Nicholas Meiler and 22 of his dependents were listed for transportation in 1653, marking the close of nearly three centuries of continuous occupation.