The site consists of little more than two crumbling drystone walls; one stretches six metres from north to south, whilst another seven-metre section extends eastward from its northern end. These modest remains, standing just over a metre high, were recorded as a castle by the antiquarian John O’Donovan in 1839, and the site has long been associated with the Mac Brody family who held sway here during the 17th century.

What makes Knockanalban particularly intriguing is its setting atop a circular raised platform, roughly 30 metres across and defined by a scarp that rises up to 1.2 metres above the surrounding ground. This elevated area, now surrounded by coniferous forest but deliberately left unplanted, has led some archaeologists to suggest it might actually be a crannog; one of those artificial island dwellings that dot Ireland’s lakes and wetlands. Local historian Gleeson even proposed in 1989 that a second crannog once existed just 50 metres to the west, though no trace of it remains visible today.

Whether medieval tower house or ancient lake dwelling, Knockanalban refuses to give up its secrets easily. The absence of any historical documentation beyond O’Donovan’s brief mention leaves us guessing at its true purpose and age. The Mac Brody connection offers a tantalising glimpse into its possible past as a minor stronghold, yet the circular platform beneath suggests something far older might lie beneath the grass and stone.