The road does not acknowledge the earthwork; the earthwork, for its part, simply continues on either side of the tarmac, worn but legible.

The ringfort, known in Irish as a rath, is a type of enclosed farmstead built and occupied across Ireland roughly between the fifth and twelfth centuries. Most were the homes of farming families, their circular banks and ditches defining a domestic space rather than a military one. At Ballymoylin, the enclosed area measures about 27 metres across, surrounded by a bank of earth and stone that still stands up to 2.5 metres high on the exterior, though it has been reduced to a simple scarp along the north-east. A shallow fosse, essentially a ditch dug to heighten the bank material piled inward, runs around the circuit at a width of 3.5 metres, and there are possible traces of a second outer bank beyond it. The entrance, a causewayed gap roughly 3 metres wide, faces east-south-east, an orientation common to ringforts across the country. To the north-north-east of the main enclosure sits a low, irregular earthen platform, measuring approximately 9 metres by 6.5 metres and rising only 0.3 metres from the surrounding ground. Its date is uncertain, but it may represent the remnant of a house platform, the compacted base on which a timber or wattle structure once stood.

The site occupies a north-east-facing slope on rising ground, a position that would have offered practical advantages in terms of drainage and outlook, even if it sacrifices the shelter of lower ground. The fosse on the southern side is now gone where the road crosses, but enough of the earthwork survives to give a clear sense of the original form.