When fieldwalking was carried out along the ploughed route in 1999, three spreads of burnt stone came to light in boggy ground at Richmond, sitting in a natural hollow edged by a low ridge. A fourth burnt spread lay close by to the south-west, suggesting that this was not an isolated episode but a place returned to, or at least a landscape that repeatedly attracted the same kind of activity.

The burnt stone spreads are the remains of a fulacht fia, a type of prehistoric cooking or processing site found in great numbers across Ireland. The typical arrangement involved a trough dug into the ground, filled with water, and heated by dropping fire-cracked stones into it; those stones, once spent, were raked aside and left in a mound or spread around the trough. Boggy, low-lying ground like that at Richmond was well suited to this, since water was reliably close to the surface. The natural hollow, defined by its ridge, would have made the spot easy to locate and return to. The fieldwalking was carried out by Hughes and O'Brien in 1999, ahead of construction work, meaning the site was identified and recorded before the road was built rather than encountered by accident afterwards.