The example at Anneville, on the southern shore of Inchiquin Lough in County Clare, follows exactly the same logic, except that the water here is a lake. A low headland, barely a metre above the surrounding ground, juts westward into the lough, and at its narrow eastern neck someone long ago threw up a curving earthen bank with a fosse on its outer face, cutting off the peninsula from the land behind it and making the headland a defensible enclosure of roughly 80 metres in each direction.

The earthworks were noted by the antiquary T.J. Westropp in 1908, who included the site in a survey of promontory forts in County Clare published in the Journal of the Royal Society of Antiquaries of Ireland. Westropp made an observation that is easy to overlook: before the lake was partly drained in modern times, the ends of the bank and fosse would have extended right down to the water's edge, completing the enclosure and making the parallels with a coastal fort even more exact. He also noted a trace of an outer mound just east of the fosse, suggesting there may once have been a more elaborate defensive arrangement than what survives. The site appeared on the Ordnance Survey six-inch map of 1842, and by the 1920 edition it was marked as an entrenchment, a label that gestures at its military character without committing to an explanation. What the earthworks lack, unfortunately, is firm dating or any artefactual evidence; an inspection in 1998 turned up no archaeological material, and the outer mound Westropp observed had by then been replaced by a modern one. A house now sits within the area the fort once enclosed, and a driveway appears to cut through the northern arm of the bank, so the site today is a palimpsest of different moments of occupation laid over one another on a quietly unusual piece of ground.