At Lisnagree in County Galway, a circular enclosure once occupied a low rise in the landscape, roughly 26 metres across, and today there is nothing left to see. No earthwork, no hollow, no visible trace of any kind survives at the surface. The site is known only because a map once recorded it.

The enclosure appeared on the third edition of the Ordnance Survey six-inch map, published in 1932, where it was marked as a circular feature of that modest diameter. Circular enclosures of this general type are among the most common archaeological monuments in Ireland, ranging from prehistoric burial enclosures to the ringforts, known in Irish as raths or lios, that were built and occupied from the early medieval period onwards, typically as enclosed farmsteads for a single family or small community. The lios element in the townland name Lisnagree suggests that local memory of such a feature was preserved in the place name long before any cartographer arrived. What the 1932 map was recording may therefore have already been a faint impression of something older, and by the time the site was formally assessed for the Archaeological Inventory of County Galway, compiled by Olive Alcock, Kathy de hÓra, and Paul Gosling and published in 1999, even that impression had gone.