Where once a formidable tower house commanded the landscape, only a fragment of the south wall remains; a solitary section measuring about 2 metres long and 3 metres high, with grass-covered foundations tracing the ghost of the building's original footprint. The castle's walls, roughly 85 centimetres thick, hint at what was once a substantial defensive structure.

Historical records from 1641 show the castle was held by Lord Ikerrin and John Purcell, who served as trustees for William O'Meagher. The Ordnance Survey Letters from the 19th century provide more precise details about the building's original dimensions, describing it as measuring approximately 9.2 metres north to south and 7.4 metres east to west, with walls that were 1.3 metres thick and stood up to 5.4 metres in height. These measurements suggest a typical Irish tower house of moderate size, built for both defence and domestic comfort.

The proximity of another possible tower house to the west indicates this area may have been of some strategic importance, perhaps controlling a route through the countryside or overseeing productive agricultural lands. Like many Irish castles, Lisdalleen likely served multiple purposes throughout its existence; as a fortified residence, a symbol of authority, and a centre for managing the surrounding estates. Today, visitors must use considerable imagination to picture the castle in its prime, though the surviving masonry and the peaceful rural setting still evoke something of its long history.