It does not look like much, and that is precisely what makes it interesting. This is a fulacht fia, a type of prehistoric cooking site found in enormous numbers across Ireland, and one of at least two within roughly thirty-five metres of each other in the same field.

Fulachtaí fia, the plural form, are among the most common archaeological monuments in the Irish landscape, yet they are also among the least understood in terms of how they were used and by whom. The typical form is a horseshoe-shaped or roughly oval mound of burnt and shattered stone, accumulated over repeated use of a nearby trough or pit. The standard interpretation is that stones were heated in a fire, then dropped into a water-filled trough to bring it to the boil, allowing meat to be cooked. Some researchers have proposed alternative uses, including bathing or brewing, but cooking remains the most widely accepted explanation. The site at Nunstown fits the general pattern: a mound measuring five metres on its longer north-west to south-east axis, two metres across, and rising to around three-quarters of a metre in height, all of it composed of the burnt material that is the signature of this monument type. The poorly drained ground around it is exactly the kind of setting these sites favour, where water was reliably close to the surface and easy to collect. A second fulacht fia nearby suggests repeated or concurrent activity in this small area, which is not unusual; clusters of these sites are known across Ireland, though the reasons for their grouping are not fully understood.