The earthwork at Lackan in County Westmeath does none of this. It occupies low-lying, poorly drained, marshy terrain, overlooked by a ridge to the east rather than taking advantage of one. That inversion alone has led researchers to question whether it is a ringfort at all.

The enclosure is sub-circular, measuring roughly 22 metres across one axis and 29 metres across another, and is defined by a bank, an inner fosse, an outer bank, and an external fosse. A fosse, in this context, is simply a ditch, typically dug to reinforce an earthen bank. What makes the Lackan site particularly difficult to categorise is a series of radial ditches that cut across the outer fosse at the west, northeast, north, and north-northeast. Inside the enclosure, two low mounds, described as resembling inverted saucers, sit alongside faint traces of cultivation ridges running northeast to southwest, and a linear depression that may once have served as a drain. The combination of a double-bank enclosure, radial features, and internal mounding does not sit easily within what is expected of a rath, the Irish term for a ringfort, which was typically a farmstead enclosed for practical rather than ceremonial purposes. The marshy ground and the mounded interior have led to the suggestion that this may instead be some form of barrow, a burial monument, though no excavation appears to have settled the question. A second ringfort sits just 30 metres to the northwest, and open bog begins roughly 530 metres to the northeast, giving a sense of how marginal and waterlogged this landscape once was, and perhaps still is.