It measures roughly 13.5 metres across at the base, narrows to about 8.5 metres at the summit, and rises only a metre and a half from the surrounding ground. On its own, it might read as a typical prehistoric burial mound of the kind scattered across the Irish landscape. What sets this one apart is what local tradition insists lies beneath it: not a chieftain, not a saint, but a pig.

According to a legend recorded by W. G. Wood-Martin in the late 1880s, a ferocious boar roamed Ulster during the era of St. Patrick. Hunted relentlessly, the animal fled southward and sought refuge in what the account calls the valley of the Black Pig, a small vale in County Sligo. It was there, finally cornered, that the creature was killed, and it is said to have been buried beneath this very mound. The Black Pig is not an obscure figure in Irish tradition; a mythological creature of that name is associated elsewhere with the churning up of the land, with boundaries, and with a great trench known as the Black Pig's Dyke that runs across parts of Ulster and Connacht. Whether this Muckduff mound belongs to the same current of folklore or represents a separate local tradition is unclear, but the convergence of a real earthwork with a named legendary animal gives the site an unusual quality, somewhere between archaeology and myth.

The mound itself is the kind of thing that rewards a slow look. The flat top is a distinctive feature, and the way it sits along the ridge gives it a presence in the landscape that its modest height alone would not suggest. The surrounding pasture remains agricultural, so access may depend on the land and the season.