It is easy to walk past without registering what you are looking at: a collapsed drystone wall, its base stones still protruding above the accumulated peat, tracing an enclosure that measures roughly seven metres from north to south and four metres from east to west. A gap of about sixty centimetres at the north-east corner marks the original entrance, defined on its northern side by a single large boulder. Another boulder has been worked into the wall at the north-west. Inside, loose stones are scattered across an interior that slopes gently down towards the south.

Drystone enclosures of this kind, built without mortar by laying and wedging stones against one another, appear throughout Kerry and the wider west of Ireland. They served a range of purposes depending on their size, setting, and relationship to other features nearby; some were livestock enclosures, others surrounded dwellings or formed part of small agricultural systems. What survives at Lettercannon is modest in scale, the kind of structure that rarely draws attention precisely because it is so understated, a rough oval of fallen stone in rough pasture, its function and date not recorded in any detail that has come down to us. The bog that has risen around its base stones is, in its way, the reason any of it remains at all, preserving the lowest courses of the wall while the upper sections collapsed and scattered across the interior over an unknown span of years.