The drumlin corridor
The drumlins of east Mayo — the low, oval hills that give Drummin its name — are the legacy of the last ice age, deposited by retreating glaciers roughly twelve thousand years ago. The 'smooth ridge' place names across this part of Connacht all refer to the same geological fact: rounded, workable hillocks of glacial till, far more amenable to small-scale farming than the bog and mountain country to the west. The land between Swinford and Ballyhaunis has been settled and farmed since the Neolithic period, and the drumlin landscape shaped how those communities spread: each ridge its own farm, each valley its own field system. The pattern is still readable in the road layout today.