The cultivation ridges at Tonybaun came to light not through dedicated archaeological prospecting but as an incidental discovery during road works: a 2003 excavation carried out ahead of a realignment of the N26 revealed that this low-lying, fertile ground had been worked, abandoned, built over, and worked again across more than a thousand years.

The ridges and furrows found at the site are narrow and somewhat irregular, running along the northwest corner and eastern edge of a burial ground that was itself established in the late fifteenth century and later used as a children's burial ground, one of many such sites across Ireland known as cillíní. The early medieval date of the agricultural activity, 467 to 648 AD, came from radiocarbon dating of a charcoal sample taken from the furrows. The ridges had been partly cut through by the burial ground and partly obscured by later lazy beds, the broad raised cultivation ridges that became widespread in post-medieval Ireland and are visible across many western landscapes today. Twenty fragments of rotary querns, the paired grinding stones used to process grain by hand, were also recovered. Several of these had been repurposed in the construction of a leacht, a low cairn-like stone monument of early Christian character, and in the settings of graves within the burial ground, suggesting that the querns, and the agricultural life they represented, were already long out of use by the time the cemetery was laid out. A metal-working site dating to the Iron Age was identified approximately forty metres to the north, and evidence of further metal-working from slightly later in the early medieval period was also uncovered, pointing to a sustained concentration of activity on this quiet stretch of the Moy's western bank.