There is no visible trace of it on the surface, no marker, no earthwork, nothing legible to the eye of a passing walker. It exists now only in the archaeological record, a keyhole-shaped hollow roughly eighty centimetres across, lying quietly beneath the grass on the southern bank of the River Shannon at Hermitage, near Castleconnell.

The furnace came to light not through deliberate excavation but as a by-product of infrastructure work. In 2001, archaeological testing conducted under licence number 01E0319, as part of the way-leave corridor for the Castleconnell Sewerage Scheme, involved stripping back topsoil across a defined corridor. What emerged in Area C was the disturbed remains of what Collins's 2001 report describes as a bowl furnace, the kind of simple smelting or firing structure, essentially a pit with one or more channel-like flues to direct airflow, that would have sustained enough heat to work metal or fire clay. This particular example had two flues: one entering from the south-south-east, measuring just under two metres in length, and a broader, less clearly defined one running to the west at over three metres long. Scorch marks survived on the base and sides of the flues, though not inside the bowl itself, suggesting the burning had been concentrated in the channels rather than the central chamber. The fill was a loose, greyish-brown silty clay packed with charcoal flecks, a piece of chert, and a clay pipe stem. Inspection of the surrounding spoil-heaps turned up axe fragments alongside 71 pieces of worked flint and 116 of chert, a significant quantity of knapped stone that complicates any straightforward reading of the site's date or purpose. As of the record's compilation by Alison McQueen and Vera Rahilly in June 2020, artefact analysis and dating were still ongoing.

The site sits at the base of a valley, close to a fording point on the Shannon located roughly sixty metres to the north-east, which offers some context for why this location might have been active at all; river crossings tend to attract activity across long periods. The furnace does not appear on Ordnance Survey historic mapping, meaning it left no cartographic trace before the sewerage scheme exposed it. There is nothing to see at ground level today, and aerial photography confirms the absence of any surface expression. For anyone interested in the archaeology of the Shannon corridor, Castleconnell itself is the practical starting point, with the Hermitage area accessible along the riverbank, though the furnace's precise location within the former way-leave corridor is not publicly marked.