A field in Coolbane, County Cork, sits on a gentle slope facing north-east, above a sharp drop of ground, and to the eye it offers nothing unusual at all. Yet Ordnance Survey maps stretching back to 1842 show a circular earthwork marked clearly on that hillside, a ringfort of the kind built across Ireland from the early medieval period onwards as enclosed farmsteads, typically defined by one or more earthen banks and ditches surrounding a central living area. By 1981, the last traces of this one had been quietly removed.

The fort had its own name, Lisin Clochach, recorded by a Bowman in 1934, when he noted it standing on land belonging to a B. Purdon. At that point it was still a double-ramparted structure, meaning it had two concentric banks rather than the single bank more commonly seen, which would have made it a reasonably substantial example of its type. Bowman estimated a diameter of around 33 yards and noted that roughly one-sixth of the outer rampart and one-third of the inner still stood. The Ordnance Survey maps tell a slightly different story about its size, recording a diameter closer to 28 metres on the 1842 and 1905 editions, and 25 metres on the 1937 sheet, which may reflect different methods of measurement or the gradual erosion of the banks over time. By 1972, local accounts confirm the fort had been levelled except for one small section beside a field fence. That remnant held on until around 1981 before it too disappeared into the pasture.