This small underground structure, measuring 3 metres by 2 metres with walls just under a metre high, is constructed with drystone walls and roofed with stone lintels. Its tiny entrance, barely 45 centimetres square, faces west towards the sea and may have been modified during the 19th century. Whilst its original purpose remains uncertain, local tradition tells us it found a second life in the 1900s as a secret location for making poitín, Ireland's infamous moonshine.

The passage sits within a remarkable landscape of ancient monuments, suggesting it may be far older than its bootlegging days would indicate. Just 285 metres to the east lies St Fanad's Cell, a hermitage site built in a strikingly similar style, alongside a collection of early Christian monuments including St. Connell's Well, St Fanad's Well, a bullaun stone, another souterrain, a standing stone, and a burial ground. The hillside itself has been shaped into a series of terraces reminiscent of those found at the famous monastic site of Skellig Michael in County Kerry, hinting at possible medieval origins connected to the nearby ecclesiastical complex.

However, the dating of this enigmatic structure remains contentious. Whilst its souterrain-like construction and proximity to St Fanad's religious sites suggest it could date from the medieval period, a small 18th or 19th century cottage just 50 metres to the north offers an alternative theory. The passage and its surrounding terraces might instead be the work of more recent inhabitants, who carved out this sheltered space and cultivated the hillside during the post-medieval period. Whatever its origins, this humble stone passage represents layers of Irish history; from possible medieval religious use to Georgian-era agriculture, and finally to its 20th century role in Ireland's illicit distilling tradition.