Hilltop enclosure, Dernacoo, Co. Monaghan
Co. Monaghan |
Enclosures
On the crest of a drumlin in Dernacoo, County Monaghan, there sits an earthen enclosure that cartographers have consistently declined to acknowledge.
Every edition of the Ordnance Survey six-inch map passed it over without a single antiquity symbol, yet the feature was there all along, quietly curving across the hillside, catalogued by the mapmakers themselves simply as a field bank.
Drumlins, the smooth elongated hills of glacial till that ripple across counties like Monaghan, frequently attracted early settlement on their elevated, well-drained summits, and this site fits that pattern. What survives is a substantial earthen bank accompanied by an outer fosse, essentially a ditch running along the outside of the bank, tracing an arc from south-south-east to west with a chord of approximately 80 metres. That is a considerable span, suggesting the original enclosure, if fully intact, would have enclosed a large area of high ground. The remainder of the perimeter has either been lost to agricultural reshaping or lies beneath the present surface, leaving the structure incomplete and its full extent uncertain. The 1834 and 1907 editions of the six-inch map both record the curving line as a field boundary, a classification that effectively rendered it invisible to anyone searching for listed monuments. It only began to attract proper attention through aerial photography, appearing on an image from the 1970s and again on later imagery from 2005, when the slight but consistent shadow of the bank and fosse became legible from above in a way that ground-level observation alone would not easily reveal.