The south-western angle of this enclosure, including a corner tower, the western wall running some 43 metres, and the western end of the southern wall extending roughly 18 metres, all appear to be medieval in origin. That corner tower is not merely decorative; a geophysical survey conducted by Gimson and Bonsall in 2014 detected two roughly parallel anomalies, each about 56 metres long and 5 metres wide, running south-westward from it, and interpreted these as a possible buried trackway. The idea that a formal approach route may survive underground, just outside the enclosure wall, gives the outer edges of the site a quiet archaeological charge that the more celebrated buildings inside tend to overshadow.

Excavation in 1988, carried out by Manning, opened up an area immediately outside the western end of the Hall of the Vicars Choral, which is the building that once housed the clergy responsible for singing the daily cathedral liturgy. The dig revealed evidence for two distinct phases of gateway on the southern perimeter. The earlier gateway pre-dates the Hall of the Vicars Choral, which was constructed in the 15th century, and a second gateway appears to have been built more or less in step with that hall. In both phases only the eastern gate-pier survived, so the full width of each entrance remains uncertain. Beneath these gateways, the excavation also uncovered foundations belonging to a structure that pre-dates the hall and appears roughly contemporary with the earlier gate, pointing to a sequence of use and rebuilding along this southern edge that stretches back well before the 15th century. Taken together, the enclosure wall, the buried gateways, and the possible trackway form a kind of stratigraphic argument in stone and soil about how people moved in and out of this hilltop complex across several centuries.