No wall, no ditch, no upstanding monument of any kind. Yet in aerial photographs taken over this part of north Cork in July 1989, the outline of a circular enclosure roughly forty metres across emerged from the soil itself, made visible only by the differential growth of crops above buried features. This is what archaeologists call a cropmark: where a buried fosse, or ditch, retains more moisture than the surrounding ground, the vegetation above it grows taller or greener, tracing the shape of something long since levelled and forgotten.

What the photographs revealed was not a simple ring. As well as the main circular fosse, the aerial imagery picked out an arc of a narrower concentric outer fosse running from the north-west around to the north-east, and a further intervening fosse visible between south-west and south-east. The arrangement suggests a more complex structure than a basic enclosure, perhaps one that was modified or elaborated over time. Linear cropmarks to the south and south-east may represent the remnants of levelled field boundaries, hinting at a worked landscape that once surrounded the site. Most striking of all is the company the enclosure keeps: several other levelled ringforts and circular enclosures have been identified in the immediately adjacent fields. A ringfort, to explain the term, is a type of enclosed farmstead typical of early medieval Ireland, usually consisting of a raised circular area bounded by one or more earthen banks and ditches. The clustering of so many such features in this small area of north Cork suggests the land around Sallypark was intensively occupied and organised at some point in the early medieval period, even if every visible trace of that occupation has long since been ploughed flat.

Because nothing survives above ground, there is no particular vantage point from which to appreciate the site on foot. Its existence is essentially photographic, a record held in the archive of a single summer survey flight more than three decades ago.