The claim is not outlandish on its face; Lough Ree, into whose south-eastern reaches this bay opens, sits on the River Shannon and would have been well within Viking reach. But the archaeology is more cautious. Despite the romantic reputation, surface evidence for a Norse presence is thin, and the site reads more readily as a native Irish promontory fort, the kind of enclosed defensive position that used natural water boundaries in place of full perimeter banking.

The enclosure is roughly oval, measuring approximately 130 metres north to south and 90 metres east to west. A promontory fort works by letting the lakeshore do much of the defensive work; here, a steep natural scarp rising from the water protects the western, northern, and north-eastern sides, while the landward approach from the north-east around to the south-west is cut off by a more deliberate arrangement of earthworks. That arrangement follows a classic pattern: an inner bank, then a fosse (a defensive ditch), then a lower, wider outer bank beyond it. The inner bank has been worn almost to a scarp, rising no more than a metre at its highest; the fosse between the two banks runs three to five metres wide; and the outer bank, flattened to about thirty centimetres, spreads five to seven metres across. Modern drainage works have cut through the fosse on the eastern side and through the outer bank to the south-east, degrading what survives. Inside the enclosure, the ground is covered by lazy-beds, the ridge-and-furrow cultivation strips associated with post-medieval and famine-era potato farming. A house site is visible in the south-east quadrant. T. Fanning of University College Galway excavated the site between 1980 and 1984, which should in time shed more light on its date and character. On the shoreline immediately to the west lies the remains of an oak-planked jetty, and roughly 35 metres to the south sits a possible burial mound, both of which local tradition also attributes to the Vikings.