The hollow, designated F1002 during research excavations at the site, was a natural depression that had been deliberately enlarged by its Late Bronze Age occupants. Its northern half was dominated by a substantial hearth, around which the evidence of daily life accumulated in layers. Beach sand was spread across the floor in at least two episodes, and the hearth itself went through distinct phases of use. Radiocarbon dates place the activity broadly between 1070 and 510 cal. BC, with one date of 1070 to 800 cal. BC from charcoal and a later date of 920 to 510 cal. BC from unburnt animal bone that may represent the period just after the hearth fell out of use. The finds recovered from around its margins tell a complicated story: nearly 8.8 kilograms of animal bone along with fish bones, limpet shells, and periwinkles point to sustained food preparation and disposal, while fifteen clay mould fragments, most of them designed for casting bronze pins, suggest that the hearth also functioned at some point as a furnace for metalworking. A small rock-cut pit to the west of the hollow, sealed with three flat slabs, is interpreted as a water-storage cistern that may likewise have served the metalworking process. Alongside all of this, two near-complete scallop shells and fragments of others were found at the hearth margins. Scallop shells are not straightforwardly explained as food waste in this kind of context, and the excavators raised the possibility that their presence points to some form of ritual use within the same space where bronze was being cast and limpets were being eaten.

The site is not separately signposted from Dún Aonghasa itself, and there is nothing visible above ground today that distinguishes this particular area of the inner enclosure. The hollow was uncovered and recorded during the research excavations published by Claire Cotter in 2012, and what it offers now is less a visible feature than a piece of reinterpreted ground: a reminder that the interior of the fort was not simply a defended space but a place where people worked metal, prepared food, and perhaps conducted rites, all within a few metres of one another.