This linear earthwork, which survives in five sections stretching 355 metres alongside the Sruhanafulla Stream, was first investigated in 2003 when 19 test trenches were excavated ahead of the N15 Bundoran-Ballyshannon bypass. The ditches varied considerably in preservation, ranging from 2.3 to 5 metres wide, though no datable artefacts emerged from these initial excavations. Local history records from 1909 tell us that Reverend Canon Naylor traced this rampart through several townlands, noting it ran parallel to the Sruhanafulla, whose name translates as 'streamlet of Blood', traditionally marking the ancient boundary of Ulster.

The site's significance became clearer during full excavations in 2004, which revealed a more complete picture of this Iron Age construction. The earthwork consisted of a central bank, up to 2 metres high in places and 8 metres wide at its base, flanked by ditches on both the northern and southern sides. Though much of the structure had been levelled by centuries of farming, with one Victorian rector admitting to destroying sections that ran through church grounds, the excavations yielded crucial dating evidence. Radiocarbon analysis of charcoal samples from the ditches produced dates ranging from AD 60 to 420 for ash and willow fragments, whilst hazel charcoal from the northern ditch dated to AD 1020 to 1250, suggesting the site saw activity across multiple periods.

The Black Pig's Dyke itself is a fragmentary defensive system known by various names as it winds across the landscape; the Worms Ditch, the Dorsey, and the Dane's Cast amongst them. Starting near Scarva on the Down-Armagh border, it traces a discontinuous path through south Armagh, Monaghan, Cavan, and Fermanagh before reaching Donegal Bay, possibly terminating at the mouth of the River Drowse. The Magheracar excavations also turned up an unexpected find: a Brown Bess flintlock rifle from around 1800, discovered at the base of the embankment's northern slope, along with post-medieval pottery and clay pipe fragments scattered through the topsoil, reminding us that these ancient earthworks continued to shape the landscape long after their original builders had vanished into history.