By 1619, Wilson had completed both a castle and a bawn, a defensive courtyard wall common to plantation period architecture in Ulster. The complex stood atop a mound called Dundree, and contemporary records from 1622 paint a detailed picture of the structure: a substantial building of lime, stone and birch timber with a slate roof, measuring 50 feet long and 18 feet wide with two wings extending from the main block. The accompanying bawn formed an impressive square enclosure, stretching 100 feet on each side with walls rising 12 feet high, projecting forward from the castle’s facade.

The fortunes of Wilson’s castle declined rapidly during the turbulent mid-17th century. By the time of the Civil Survey in 1654-6, just over thirty years after its detailed description, the once-imposing structure had already fallen into ruin and was recorded as ‘a ruinous castle belonging to ye haire of Mr Wilson called Wilson’s fort’. The deterioration continued over the following centuries; when antiquarian Fagan visited the site in 1846, only fragmentary sections of the bawn and castle walls remained, insufficient to determine the original layout or full extent of the complex.

Today, no visible traces of Wilson’s 17th-century stronghold survive above ground. The mound upon which the castle once commanded the surrounding countryside is now occupied by a modern house that bears the historic Killynure name, serving as the sole reminder of the plantation-era fortress that once stood here. Archaeological surveys have documented the site’s location and historical significance, ensuring that while the physical structure has vanished, its place in Donegal’s complex plantation history remains recorded.