The rath at Radestown sits at the summit of a steep-sided hill in open pasture, and what makes it worth a second look is how much of its original structure survives, even if not all of it has come through unscathed. A rath is a ringfort, the most common monument type in the Irish landscape, typically a circular enclosure defined by earthen banks and ditches and associated with early medieval farming settlements, dating roughly from the fifth to the twelfth century. This one is modest in scale but carefully formed.

The enclosure measures approximately eighteen metres in diameter, ringed by an inner bank, a wide flat-bottomed fosse (that is, a ditch), and an outer bank beyond that. The inner bank rises about sixty centimetres above the interior ground level but stands over two metres high when measured from the base of the fosse on the outside, giving a sense of how the topography was manipulated to create a defended or at least clearly bounded domestic space. An original entrance and causeway, three metres wide, survives on the south-south-west side, where the fosse would have been bridged to allow passage. The interior slopes noticeably to the south, dropping around one and a half metres across its width, which is an unusual feature and one that would have shaped how any structures within were positioned. The relatively sparse vegetation inside makes the slope easy to read from ground level. Not everything has survived intact, however. The southern sector of the fosse and outer bank was levelled at some point to accommodate a water treatment plant built adjacent to the site, a small but telling reminder of how even well-preserved monuments sit inside a landscape that keeps being put to new uses.