A slight change in level, a scarp more noticeable on the northern side than anywhere else, traces a rough circle about thirty metres across. This is a rath, the Irish term for a ringfort, the type of enclosed farmstead that was built in its thousands across Ireland during the early medieval period, roughly between the fifth and twelfth centuries. Most were defined by one or more earthen banks and ditches, enclosing a space where a farming family would have lived, kept animals, and stored food. The example at Shean is modest and largely levelled, but the underlying form has not entirely disappeared.

What makes this particular site quietly telling is the way the modern landscape has grown over and through it. A field boundary running north to south cuts across the eastern half of the interior, the kind of incremental land division that has obscured or erased countless similar monuments across the Irish countryside. The northern scarp remains the clearest feature, suggesting that whatever earthwork once defined this enclosure survived best on that side, whether through accident of drainage, tillage patterns, or the particular way the ground was managed over the centuries. The overall diameter of around thirty metres is fairly typical for a single-banked rath, which would have been a working agricultural enclosure rather than a defensive fortification in any military sense.