Measuring roughly 15 metres east to west and 8 metres north to south, this faint feature appears on Ordnance Survey maps from 1839 and 1925 simply labelled as 'Site of Castle'. Located about 300 metres south of a col on the hill's northeastern side, the spot now shows nothing more than pasture to the casual observer, leaving its story frustratingly incomplete.

What makes this site particularly intriguing is its complete absence from historical records. No castle at Lacken appears in any known documents, and the townland itself doesn't even warrant a mention in the comprehensive Civil Survey of 1654-6, which catalogued Irish lands following the Cromwellian conquest. This silence is unusual; most castles, even minor tower houses, left some paper trail through ownership records, legal disputes, or military accounts. The mystery deepened in 2008 when archaeological testing about 100 metres northwest of the site yielded no related artefacts or building materials that might confirm a medieval structure once stood here.

The designation on those 19th and early 20th century maps likely came from local tradition or perhaps visible ruins that have since vanished completely. Early Ordnance Survey teams often relied on local knowledge when mapping, recording place names and sites that residents identified as significant. Whether this was truly a castle, a fortified house, or perhaps a case of mistaken identity passed down through generations, the earth keeps its secrets well. Today, the site serves as a reminder of how much of Ireland's medieval landscape has been lost, not just physically but from memory itself.