Between 1702 and 1708 the whole of the city walls was converted into a raised walkway and it is likely that the tower was modified as part of this process.

Its plan is semi-octagonal, and it appears to be the outer part of a drum tower without its upper storeys.

The lower chamber contains three loops (unglazed slit windows), and at the level of the walkway are the springers of a former vault.

During the 1994–95 alterations, the stone parapet between the walkway and the tower was replaced by an oak-framed polycarbonate screen.

The citation in the National Heritage List for England states that this "masks its former defensive features and purpose".