What remains of the ringfort at Rathangan sits not in that eastern field but just to its west, a D-shaped patch of grass and scrub defined by a low scarp roughly a metre high, measuring about twenty metres along its longer axis and only five metres across at its widest. A field bank running roughly north-north-west to south-south-east has cut through most of the original structure, leaving this fragment as the principal visible trace. Ringforts, or raths, were typically circular earthen enclosures used as farmsteads during the early medieval period in Ireland, their banks and ditches marking out a defended domestic space for a family or small community.

The local name for the site is Rathavsree, understood to derive from the Irish Rathamhaistir, meaning the master's rath. That prefix suggests the enclosure was associated with a person of some standing in the local hierarchy, though nothing more specific about its original occupants has been recorded. The site lies at the edge of a fairly level stretch of ground that slopes gently down towards a small north-south stream about a hundred metres to the west, a typical positioning for a rath, close enough to water to be practical but on slightly elevated or firm ground. The eastern field, despite showing no physical trace of the enclosure, has preserved the memory of the site through its name alone, a quiet form of folk cartography that has outlasted the earthwork itself.