The method involved heating stones in a fire, dropping them into a water-filled trough to bring it to the boil, and using the hot water to cook meat. The stones crack and blacken with repeated heating, and it is precisely this scorched, fragmented material, known as burnt mound material, that survives in the ground long after everything else has gone.

What makes the site at Pluckanes particularly notable is not the single fulacht fia but the fact that it sits in company. Two further examples of the same type lie within the same field, one approximately fifty metres to the north-north-east and another roughly eighty metres to the north-east, both now levelled. The ground itself offers a clue to why this spot attracted repeated use: it was formerly marshy, and has only recently been reclaimed for agriculture. Fulachta fiadh are very commonly found in low-lying, wet ground, close to a reliable water source, which would have been essential to the whole process. The clustering of three sites within such a short distance of one another suggests the area was returned to again and again, perhaps across generations, for the same purpose.

The burnt material is visible as a spread in the ploughed field, which means the site is most legible when the soil has been turned. The formerly marshy character of the ground is worth bearing in mind when visiting in wetter months.