At Glenleigh in County Cork, a ringfort, known in Irish as a rath, once stood on the northern edge of a steep drop down to the Owenbaun River valley. A rath is a roughly circular earthen enclosure, typically dating from the early medieval period, built as a farmstead and defended by one or more raised banks and ditches. This one measured approximately thirty metres in diameter, a modest but typical size. Today, there is nothing left to see. The land has been levelled, and the pasture gives no indication that anything ever stood here.

What makes the site quietly significant is the paper trail left by the Ordnance Survey. The 1842 six-inch map shows the enclosure clearly, rendered in the hachured style that cartographers of the period used to suggest earthworks and raised ground. By the time the same area was mapped again in 1904 and 1936, only an arc running from the north to the south-east was still being recorded, suggesting that by then the earthwork had already been substantially reduced. The progression across three maps tells a familiar story of gradual agricultural clearance, the kind of slow erasure that happened to hundreds of similar sites across Munster over the nineteenth and twentieth centuries. The valley of the Owenbaun River below would have made this a practical location for an early farmer, with water close by and a natural defensive advantage provided by the steep slope to the south.