At Corballis, in the barony of Nethercross in north County Dublin, there is a site that appears on Ordnance Survey maps across a century of editions, and yet there is nothing whatsoever to see. No mound, no earthwork, no visible trace of any kind remains above the surface of the ground. What the maps record, in both 1837 and 1937, is the "site of moat", marked on a break in slope that looks out over the Malahide estuary. The label itself requires a small clarification: in Irish archaeological usage, "moat" is an older anglicisation of "motte", referring to the raised earthen mound that formed the focal point of an early medieval Norman fortification, a motte and bailey. The motte typically supported a timber tower, while the adjacent bailey enclosed the associated settlement. That such a feature was recorded here at all, even as a ghost on a map, hints at a now-vanished episode of Norman settlement along this stretch of the Dublin coastline.

The two Ordnance Survey editions that document this site span exactly a century. The first, from 1837, was produced during the great national mapping project that brought systematic cartographic coverage to the entire island for the first time. That the surveyors noted a "site of moat" rather than the moat itself suggests the earthwork was already largely lost by that point, surviving perhaps only as a faint swell in the ground or in local memory. By the time the 1937 edition repeated the designation, whatever physical evidence had remained was presumably no further advanced. The site was compiled as part of an archaeological inventory by Geraldine Stout and updated by Christine Baker, with the record uploaded in January 2015.

Visitors to Corballis today will find the landscape shaped primarily by the coastal amenities around Malahide, with the estuary providing the broader orientation. The break in slope that once gave the motte its commanding position overlooking the water is the only geographical clue to where the earthwork may have stood, though without specialist survey equipment there is no realistic prospect of identifying its footprint. The site serves less as a destination in its own right and more as a prompt for thinking about how much of the Norman presence in County Dublin has quietly disappeared into farmland and coastal erosion over the intervening centuries, leaving only a cartographic annotation where a fortification once rose.