Castle Gatehouse, Entrance Gateway, Side Walls, Linking Walls and Front Wall

The Castle Gatehouse, along with its entrance gateway, side walls, linking walls, and front wall, is a significant medieval structure that has undergone alterations in the 16th century for Bishop Tunstall and around 1790 in the style of architect Wyatt for Bishop Barrington. The gateway likely dates from around 1790, while the walls are probably from the 18th and early 19th centuries. The building is constructed of coursed squared sandstone with ashlar dressings, featuring an ashlar gateway and flanking walls.

The gatehouse stands three storeys tall and consists of three bays. It has a moulded round arch made up of four orders, supported by shafts with scalloped or chevron-moulded capitals. This arch is flanked by battlemented projections that contain two-centred-arched windows with intersecting glazing bars beneath dripmoulds. Above the arch, there is a similar window and a rose window, all set under a battlemented parapet. The corner turrets are also battlemented and feature blind cross slits above blind quatrefoils. The rib-vaulted arch includes a lion-carved boss.

The entrance gateway features two octagonal piers with a frieze and battlemented coping, topped with wrought iron scrolls that support square gas lamps. Short sections of wall on either side of the gateway have blind cross slits.

The front wall facing Palace Green is a high wall with roll-moulded coping that extends along the front to the Green. A slightly lower section with sloped coping continues in front of University College Master's House to Owengate.

The linking walls between the gateway and gatehouse, the gatehouse and the castle's north and west ranges, and the gatehouse and keep are all battlemented. These walls contain Tudor-arched doors, blind cross slits, and wide buttresses. A fountain is set into the courtyard side of the wall linking the gatehouse with the north range, featuring a moulded semicircular projection on a pedestal beneath a renewed Tudor arch.