A ringfort near Doonally in County Sligo fits precisely that description. Where an enclosed settlement once occupied a gentle north-facing slope in open pasture, the ground today shows nothing at all. The earthworks have been levelled, and there is no visible surface trace remaining.

Ringforts, the most common monument type in the Irish landscape, were typically circular or oval enclosures defined by one or more earthen banks and ditches, used as farmsteads during the early medieval period. This one was D-shaped rather than fully circular, a form that sometimes reflects the incorporation of a natural feature or an existing boundary into the enclosure design. Its straight southwestern side, approximately 21 metres long, ran along what became the townland boundary between Willowbrook and Doonally, and that line is still legible on both the 1837 and 1912 editions of the Ordnance Survey six-inch map. The curvilinear northeastern arc, with a maximum dimension of roughly 22 metres, sat within Willowbrook townland. On the 1912 edition this curved portion was depicted with hachures, the short parallel lines cartographers used to indicate an earthen bank or raised feature, suggesting it was still a physical presence on the landscape at that point, even if reduced.

What makes the site worth attention now is precisely this gap between the cartographic record and the present ground. The townland boundary that follows the old southwestern wall is among the last material traces of the enclosure's existence, a property line quietly preserving the geometry of a settlement that may be over a thousand years old.