Section of Boundry Walls around Castle grounds running E from outer Gatehouse

This section of boundary walls surrounds the castle grounds and runs southwest and east from the outer gatehouse on Market Street. The wall is made of rubble and extends southwest from the outer gatehouse, acting as a revetment wall for the elevated outer ward above Wogan Street, and features some crenellations. It makes a right-angle turn to the southeast above Island House, which is a ruined garden wall likely from the 18th century, and incorporates part of the late 13th-century curtain wall that adjoins the southwest castle tower at its southeastern end.

A second section of the wall runs east from the outer gatehouse. The western end is made of rubble, while the majority of the wall is constructed from late 18th-century to early 19th-century Flemish bond brick, built against an earlier rubble wall on the northern side. There are arched openings, one of which has classical detailing, leading to the garden of Castle House. On the northern side, there are rubble lean-tos with slate roofs.

Additionally, a rubble wall with some ruined crenellations runs at right angles along the cliff edge towards a gazebo and descends to the foreshore.