A military fortification once occupied this stretch of riverbank, built not on solid ground but on made ground, meaning ground that had been artificially raised or filled to support construction. It has left no visible trace whatsoever.

The structure in question was a demi-bastion, a half-projecting defensive platform of the kind typically angled outward to allow defenders to cover the face of a wall without exposing themselves to direct fire. This one dates from the Cromwellian period, the 1650s, when Parliamentary forces reorganised and strengthened garrison towns across Ireland. Rather than being built as a freestanding structure, it was constructed hard against an existing medieval wall, which ran roughly south-west to north-east along the eastern side of what had been a Friary complex. The bastion was, in other words, a seventeenth-century military addition grafted onto a much older urban fabric, occupying a narrow strip of riverbank that had to be built up before it could bear the weight of fortification at all. The relationship between that earlier Friary and the defensive wall it sat behind suggests a layered landscape where religious, civic, and military uses accumulated over centuries on the same ground.