Exterior
Rubble stone walls of various dates. N of the churchyard wall of St. Mary's a ramp giving rear access to Nos 6-10 Main Street (Somerfield's), step outward to rear wall behind Nos 6-10, and straight joint to 3m square section, the one section collapsed of some 15m then some 9m of roughcast wall to rear of Nos 12-14, roughcast section on bedrock and rebuilt outside steps to garden of No 16. High wall on grass bank to left, ivy-clad section stepped forward for some 9m, then ramp to garden gate, about 5m of high wall then lower for 4m, mostly roughcast retaining wall before step out of some 2m and run of some 10m with blocked door to right. Further projection of some 4.5m, length of 6.5 m before return of some 7m (behind Nos 24-6). Blocked doorway in E return. Long stretch of undulating rubble wall partly on bedrock, some 51m to quadrant curve forward, another 34m to broad ramp leading up to break for Morgan's Way (between Nos 50 and 52). A probably C17 double barbican tower is shown on this section in Buck engraving of 1748.
E of Morgan's Way, rubble wall partly ivy-clad and irregular behind ramp, door raised up some 27m from Morgan's Way, wall then in poor condition and lower for considerable length, some sections missing , before projection behind No 74 of some 4m. Garden door to No 74. To S, in gardens of Nos 64-72, is stretch of retaining wall halfway down gardens. Further doors in main wall to W, which is high from approx. rear of No 82, not a retaining wall, running some 80m before dropping down again to low wall and curving sharply back onto rocky overgrown bank behind Nos 6-14 East Back. On the line of the main walls below, a low section of partly collapsed rubble wall skirts the N edge of the wooded bank behind the Baptist Chapel and St. Michael's Church.
From a point N of St. Michael's Churchyard E as far as Barnard's Tower the remains of the Town Walls are a Scheduled Ancient Monument. Walls here are partly rebuilt or repointed running to a curved projection behind No 110, before access ramp to Blackhorse Walk. This section has some arrow-slits and various square small openings possibly put-log holes, a projection of some 3m, two outside ramps, then small round tower with splayed base and arrow-slits.
Beyond Blackhorse Walk, a raised terrace of some 29m leads to Barnard's Tower with high retaining wall on back, behind Nos 120-2, and rubble stone restored parapet on retaining wall to other side. Tower is a circular corner tower with square entrance tower projecting to W. Restored flat parapets with drain holes. Entrance tower has entrance at upper level from the raised terrace. Flight of 8 rebuilt curving steps from terrace up to tall segmental-pointed doorway with stone voussoirs. Two small square holes above to either side and two loops in upper level, parapet considerably higher on right. N side of entrance tower has flat parapet continued from W side, loop at upper level (entrance level from terrace) and two square drain openings with stone sills above.
Main round tower has splayed high basement and main chamber at upper level. Long loop each floor on NW and small loops at intermediate levels to right in angle to entrance tower. N side long loop to basement and pair of lancets above with stone voussoirs. Relieving arch over. Small square drain openings with stone sills below high flat parapet. NE long loop each floor. Entrance passage is stone vaulted and had gate and portcullis. Door on right, portcullis slot and splayed reveal to arrowslot each side. Segmental-pointed part-blocked entry to round tower upper chamber. This room is stone vaulted and has fireplace and latrine shaft.