The Ordnance Survey map, perhaps optimistically, marks the site as 'Altars' in the plural, but there is only one such feature, and even in its better days it was not an imposing thing. It sits just 1.5 metres south of a stone-built cell and measures barely two metres across, its flat-topped surface now collapsed into a loose pile no more than 0.6 metres high.

The antiquarian T. J. Westropp visited in 1911 and described what he found as 'a shapeless heap of uninscribed slabs', which is either frank or unkind depending on your expectations. More interesting to him were the objects placed on top: rounded pebbles gathered from the nearby beach, and two so-called anchor stones, large blocks with a groove worn around them for a rope. Westropp interpreted these as votive deposits left by fishermen giving thanks, presumably for surviving whatever the Atlantic had thrown at them. The beach pebbles have since disappeared, but one of the anchor stones remains. It is, as it turns out, not a man-made artefact at all but a geological curiosity, formed by the differential weathering of sandstone bands into a naturally grooved shape. Whether the fishermen who left it there knew this, or cared, is another matter entirely.