A fulacht fia is a Bronze Age burnt mound, typically formed beside a stream or boggy hollow, where stones were heated in a fire and then dropped into a water-filled trough to bring it to the boil. Over repeated use, the shattered, heat-spent stones were discarded to the side, building up the horseshoe-shaped mounds that survive in their thousands across the Irish countryside. They date broadly from around 1500 BC, though examples range earlier and later, and their precise function has been debated, with cooking the most widely accepted explanation.

The site at Rubble is one of many such monuments recorded across Mayo, a county whose boglands have preserved these features with unusual fidelity. The waterlogged conditions that make the terrain difficult to farm are precisely the conditions that slow the decay of organic material and protect low earthworks from the plough. The townland name itself, Rubble, carries no obvious connection to the monument, and is more likely a phonetic anglicisation of an earlier Irish place-name. Beyond its classification and location, the documented detail for this particular fulacht fia is limited, which is not unusual for a monument type that is common enough to have been catalogued in large numbers but individually understudied.