The Ordnance Survey's 1837 six-inch edition recorded nothing here, yet by the 1940 revision a D-shaped hachured area had appeared in the pasture at Tullnagracken, sitting quietly on a westward-facing slope as it presumably had for well over a thousand years before either cartographer came along.

What survives is a slightly raised oval enclosure, roughly 39 metres north to south and 32 metres east to west, the kind of modest dimensions typical of a rath, the earthen ringfort that was the standard farmstead form across early medieval Ireland. A rath of this type would originally have enclosed a household, its function both practical and social, marking territory and providing a degree of security for people and livestock. At Tullnagracken the defining features are still legible on the ground: a low scarp running from the south-east around to the west, an earthen bank along the western and northern arc, and faint traces of an external fosse, a defensive ditch, visible at the north-west. The bank measures about 2.3 metres wide, modest but intact enough to read. On the north-north-east to east-south-east side, the enclosure boundary has been absorbed into a modern field wall that follows the public road, which accounts for the flat eastern edge that gives the whole site its D-shaped appearance when viewed from above. The interior of the enclosure tilts gently from east to west, simply following the natural slope of the hillside rather than any deliberate landscaping.