What makes it quietly peculiar is not just what it is, but what lies nearby: another of its kind, almost identical in character, barely forty metres to the north-west. Two fulachtaí fia, side by side in the same field, each a low hump of earth and scorched debris.

A fulacht fia is a type of burnt mound found in enormous numbers across Ireland, particularly from the Bronze Age onwards. The typical interpretation is that they functioned as outdoor cooking sites: a trough dug into the ground would be filled with water, and stones heated in a nearby fire would be dropped in to bring it to the boil. Over time, the repeatedly cracked and spent stones were raked out and piled to the side, forming the characteristic horseshoe or oval mound that survives today. The Classes example was recorded on the Ordnance Survey six-inch map of 1938 as an oval mound, and a spread of burnt material has been noted at the site, consistent with that pattern of use. Whether the two neighbouring mounds represent two distinct phases of activity, two separate work areas used simultaneously, or simply the gradual accumulation of debris from a single long-used location is not clear from what survives above ground.