Exterior
High coursed rubble-stone wall in several straight sections forming an irregular plan and a circuit approximately 730m long, with 2 gate houses (listed as separate items) and eight 2-stage round towers contrasting with the polygonal towers of the castle. The quality of masonry in the wall is variable, accounted for by various repairs and restorations. The towers have mainly open gorges and were originally crossed by timber bridges, one of which has been repaired on the NE side. The upper stages of the towers have arrow loops, while the embattled parapet, where it survives, has similar loops to the merlons. The walls have regular brattice slots. At the SE end the wall has been demolished across Castle Ditch and begins on its N side, where on the inner side facing Hole-in-the-Wall Street stone steps to the wall walk survive at high level, and where there is a postern gate, known as the Greengate, under a 2-centred arch with portcullis slot. The adjacent tower has a shouldered lintel to a fireplace in the upper stage. The wall, with 2 towers and the East Gate to High Street, continues on a high bank, around to the N side facing Bank Quay. The NE tower survives to the full height of its battlements and has stone steps on the inner side. A skewed archway has been inserted leading to Northgate Street. Further W, an inserted segmental arch spans a double-carriageway entrance to Market Street, while the tower on its W side also retains stone steps. A lower segmental arch leads to Church Street immediately to the E of the church.
On the NW side the church of St Mary is integral with the Town Wall and its NW, or Bell Tower, houses the vestry, while its upper storey served as a priest's dwelling. Facing N it has a 2-light Tudor window under a hoodmould, with sunk spandrels, while the W face has a plainer 2-light window in the upper stage. On the parapet is a gabled bellcote. A blocked former postern gate is on the return facing the promenade, incorporated into the church. The next tower facing the promenade is the Bath Tower, which has early C19 detail in connection with the baths established in 1823. It has its doorway in the S side facing the Promenade, which has a pointed arch with studded boarded door and Y-tracery overlight. In the N and S faces the upper stage has restored 3-light mullioned and transomed windows incorporating iron-frame casements, and restored embattled parapet. A 2-storey projection with parapet is built behind. At the W end of the High Street is the former gatehouse known as Porth-yr-Aur, beyond which there is a single tower behind the former jail. The tower is enclosed at the rear by a late C19 wall with segmental arch flanked by small-pane windows under lintels. Further S is a segmental arch across Castle Ditch, on the S side of which the reveal and part of the keyed arch of an earlier gateway is visible, while the wall abutting the castle is an addition of 1326.