In the townland of Carrownacreevy in County Sligo, an ancient enclosure sat on an east-west ridge above a stream without earning so much as a mark on the 1837 OS six-inch map, the great Victorian exercise in cataloguing Irish landscape and settlement. By the time the 1913 edition was produced, it had been recorded as an oval shape measuring roughly 27 metres on its north-east to south-west axis and about 22 metres across, a modest but deliberate form pressed into the hillside.

Enclosures of this kind, defined banks or ditches forming a roughly circular or oval boundary, are among the most common prehistoric and early medieval monument types in Ireland, often associated with settlement or livestock management, though their precise function varies considerably from site to site. What makes this one notable is less its form than its near-disappearance. The enclosure has been levelled, likely through centuries of agricultural use, and yet a slightly raised outline, still reaching a maximum dimension of around 25 metres, can be picked out in the ground surface. It sits on the ridge with a stream running roughly 70 metres to the east, a detail that suggests, as with so many Irish enclosures, that the choice of location was far from accidental; proximity to water mattered.