At Crohane in County Cork, that is precisely what survives: an oval earthwork, roughly 25 metres from north to south and just over 32 metres east to west, sitting on a south-east-facing slope that has long since been brought into tillage. The enclosing scarp is the defining feature, the raised lip of earth that would once have marked the boundary between a farmstead and the wider landscape around it.

This type of monument is known as a rath, the Irish word for a ringfort, the most common archaeological field monument in the country. Ringforts were typically the enclosed homesteads of farming families during the early medieval period, roughly from the fifth to the twelfth century, though many were built and used across a wide span of time. They range from simple earthen banks to elaborate multi-vallate enclosures with deep ditches, and they could shelter a single family or a more substantial household with outbuildings and livestock. The Crohane example is a modest one by those terms, its single scarp doing the work that a more elaborate site might have spread across several concentric earthworks. The interior is not level; it slopes downhill from north-west to south-east, and there is a slight depression in the south-east quadrant, a detail that might once have had a practical purpose, whether drainage, a sunken floor, or simply the slow settling of the ground over many centuries.

Because the site sits within a working tillage field, its visibility and condition will vary with the agricultural season and the nature of whatever crop surrounds it. The scarp itself is the thing to look for, a gentle but distinct rise of earth that traces the oval perimeter and sets the interior apart from the field beyond it.