Known as Structure E, it is one of several clocháns, the term for dry-stone corbelled or walled cells associated with early monastic settlements, built against the inner face of the site's enclosure wall. What makes it quietly odd is not its age or its construction, but what excavation failed to find: almost nothing. For a building that survives in reasonably legible form, it gave up very little of its past.

The structure is rectangular in plan, measuring 5.5 by 2.8 metres internally, with walls averaging 1.4 metres thick that survive to a maximum height of just 0.65 metres. An entrance set into the north wall, one metre wide, is now blocked by a single upright slab. The wider site, identified as Calluragh burial ground or An Cheallnúach, sits roughly 1.25 kilometres east of the village of Ballyferriter, on approximately the highest point in the townland, with an open view northward over Smerwick Harbour. Structure E was catalogued and described by J. Cuppage in the 1986 Dingle Peninsula archaeological survey, which remains a foundational reference for the region. Whatever the building's original purpose within the monastic enclosure, the working conclusion is that in more recent centuries it was put to use as an animal shelter, a fate that would explain both the absence of significant finds and the blocked entrance.