The site at Lurganboys is a crannog, an artificial or semi-artificial island constructed in a lake, typically during the early medieval period, and used as a defended homestead or place of refuge. What makes this particular example quietly compelling is how thoroughly it has been swallowed by time. The lake it once sat in, Attaduff Lough, no longer exists as open water. The whole basin, originally a roughly rectangular body of water measuring around 350 metres north to south and 340 metres east to west, has given way to overgrown marsh, leaving the crannog stranded in a landscape that no longer resembles the one it was built for.

The only clear record of the crannog as a distinct feature comes from the 1834 edition of the Ordnance Survey six-inch map, which shows a small oval shape within the lake, measuring approximately 40 metres on its longer axis and 15 metres across. That survey, produced during the first systematic mapping of Ireland, captured the lough before it had completely silted and drained away. What the cartographers recorded is now the main evidence that anything deliberate and human-made lies out there at all. The marsh has since closed over it, and the site is recorded as inaccessible.