It is roughly horseshoe-shaped, about five metres long, four metres wide, and only half a metre high, with a two-metre opening facing south-west. To the untrained eye it might read as nothing more than a weedy hump in a field margin. What it actually represents is one of the most common prehistoric monument types in Ireland, and one of the least celebrated.

This is a fulacht fia, the term used for the characteristic mounds left behind by ancient outdoor cooking or heating sites. The basic method involved heating stones in a fire, dropping them into a water-filled trough to bring it rapidly to a boil, and then discarding the cracked, spent stone nearby. Repeated over time, those discarded stones accumulated into the distinctive horseshoe shape, with the open end typically corresponding to where the trough once sat. They are found in their thousands across Ireland, usually close to water and in low-lying or boggy ground, which is precisely where this example sits, on the east bank of a small stream at Horsemount. What gives it a degree of added interest is that it does not stand alone. It belongs to a cluster of three such monuments in the same area, suggesting repeated or communal use of this particular stretch of wet ground over what may have been a considerable period of prehistoric activity.