Fort, Aghnaskew, Co. Monaghan

What makes it worth a second look is the exposed rib of bedrock running through the interior, a natural feature that whoever chose this spot would have encountered and worked around, or perhaps deliberately incorporated. The entrance is aligned to the east-south-east, following the line of the spur itself, so that anyone approaching would have had to walk along the ridge to reach it.

This is a rath, the most common type of enclosed settlement in early medieval Ireland, typically consisting of an earthen bank and ditch enclosing a roughly circular area where a farmstead once stood. At Aghnaskew the enclosure is slightly oval, measuring around 38.5 metres north-north-west to south-south-east and 34.5 metres in the other direction. There are two concentric banks separated by a berm, a flat platform of ground between them, which is a feature associated with higher-status ringforts. The inner bank survives to a reasonable height, particularly on the south-west side, where its base is over six metres wide. The outer bank is more modest and has been largely lost on the west-north-west side, where the natural slope drops away steeply enough to have made an artificial defence redundant. The builders seem to have understood the topography and adapted their construction accordingly, relying on the hillside itself where the earthwork would have been least necessary.