A low curving scarp, roughly 29 metres along its arc and just 1.2 metres high, bends across a field boundary in County Sligo's pastureland, overlooking a stream to the south. That curve is almost certainly a remnant of something older and more substantial, but by the time it entered recorded history, it had already been pressed into a very different kind of service.

A rath, in the Irish archaeological sense, is an enclosed farmstead of the early medieval period, typically a roughly circular area surrounded by one or more earthen banks and ditches. The example at Carrowwilkin appeared on the Ordnance Survey's six-inch map of 1838 as a large embanked oval, measuring approximately 45 metres on its northeast-to-southwest axis and 30 metres across. What makes the site quietly peculiar is the detail that sits alongside it on that same map: a limekiln marked on the bank at the southeast. A limekiln is a relatively simple industrial structure, used to burn limestone at high temperatures to produce quicklime for agricultural use, mortar, or whitewash. Someone had built one directly onto the old earthwork, and the surviving arc of the bank may have functioned as a ramp leading up to it. The ancient enclosure, in other words, had been absorbed into a later agricultural routine, its fabric convenient rather than venerable.

The site is listed as a possible rath rather than a confirmed one, which is an honest reflection of how much has been altered or lost. What remains is a single arc of scarp in ordinary pasture, its original extent readable only through that 1838 map record. The limekiln itself appears to be gone, leaving a landscape that now holds two absences where once there were two distinct phases of use.