Walk the ground and nothing announces itself; the landscape offers only tussocky grass and the kind of unremarkable ridge that dots the west of Ireland in their thousands. The site only becomes legible from the air, where an aerial photograph reveals an oval outline roughly twenty metres across, the ghost of a levelled bank and an external fosse pressed into the earth like a faint watermark.

A rath, the Irish term for a ringfort typically formed by an earthen bank and surrounding ditch, was the standard farmstead of early medieval Ireland, home to a family of some local standing. Hundreds survive in varying states across the country, some dramatically upstanding, others so worn by centuries of agriculture that they survive only as soil marks or crop marks visible from altitude. This example in Bullaun falls into the latter category. The enclosing bank has been levelled entirely, and the fosse, the defensive ditch that once ran around the outside, has silted or been filled to the point of invisibility at ground level. What the aerial photograph captures is the differential in soil moisture or vegetation growth that betrays the buried outline beneath, a kind of archaeological shadow. The approximate diameter of twenty metres places it at the smaller end of the rath spectrum, consistent with a single-family enclosure rather than a more elaborate multivallate site.