The north-western wall of the enclosure backs directly onto a cliff face roughly twenty metres high, so that any defender standing there would have had nothing but air behind them. This category of monument, known as a cliff-edge fort, uses the natural drop as a substitute for masonry, relying on an unscalable drop in place of a constructed wall on at least one side. At Poulacarran, that arrangement is still legible, even if much of what remains above ground is now a low, rubble-spread tangle of stone and vegetation.

The fort measures around twenty-three metres along its main axis and is enclosed on all sides except the cliff edge by a stone wall, originally somewhere between two and two and a half metres wide. An outer enclosure surrounds the whole structure, making this a more complex, layered defensive arrangement than a simple ring. The site appears on Ordnance Survey maps from 1842 and again in the 1920 edition, which tells us it was at least recognisable in the landscape throughout the nineteenth and early twentieth centuries. The antiquary Thomas Johnson Westropp visited in or around 1911 and recorded details that have since vanished: a slab-lined entrance with a stone lintel at the south-east, and two vertical joints visible in the outer wall-face at the north. By the time of a systematic inspection in 1997, the entrance had already been destroyed, apparently shortly before Westropp's visit, and no trace of it could be found. The northern outer wall-face remains the best-preserved section, built from large, horizontally laid blocks in the dry-stone manner typical of Burren construction. Elsewhere, both the inner and outer faces are heavily denuded and buried under stone spill, with the total spread of collapsed material reaching up to nine metres wide in places. A small modern drystone structure has been built directly onto the rubble at the north-east, and a low modern wall runs along the cliff edge at the north-west, perhaps to discourage livestock from going over.

The fort sits above the Poulacarran and Eanty valleys, with views sweeping from south-west to north-east through the characteristic grey-and-green Burren landscape. The hazel wood covering the shelf makes the enclosure easy to miss at ground level, and the gradual slope of the shelf gives little warning of how abruptly the cliff edge arrives.