Roughly circular and about 24 metres in diameter, it reads less as a dramatic ruin than as a quiet interruption in the landscape, its boundary wall so worn down that it barely registers against the surrounding ground.

The enclosure is defined by a stone wall roughly 1.5 metres thick, though what survives above ground stands only about half a metre high on both its inner and outer faces. A cashel, for those unfamiliar with the term, is a type of early medieval stone-walled enclosure, typically circular, used to enclose a farmstead or settlement. This annexe is conjoined to the cashel wall, joining it at the south and south-west, which suggests it was a deliberate addition rather than a separate structure built nearby. Whether it served as a stock enclosure, a working yard, or something else entirely, the record does not say. The interior is level and scattered with moss-covered rocks, which gives it a quietly neglected atmosphere, the kind of place that has been slowly subsiding into the ground for a very long time.

Carrowmore itself is a landscape already dense with prehistoric and early medieval remains, and this modest annexe sits within that broader context without drawing much attention to itself. Its interest lies partly in what it implies: that the cashel it adjoins was not simply a single enclosed space but part of a more considered arrangement of walls and yards, shaped over time by people whose specific purposes are now largely beyond recovery.