Her Majesty's Prison: Wings A, B, C and F including former chapel wing

Her Majesty's Prison, which includes Wings A, B, C, and F along with the former chapel wing, is a prison extension built between 1848 and 1849 by Thomas Smith. The structure is made of red brick laid in English bond and features slate roofs with pedimental gable ends and a hipped roof at the center. It has brick axial stacks and a large hexagonal ventilation flue.

The building has a T-shaped plan, with wings radiating from a central hall that contains galleried cells opening onto axial wells. It stands three storeys high and features mostly small segmental arched windows with stone cills, along with large recessed round arch windows at the ends of the wings that rise into the gables. The eaves are adorned with brick modillions. The central hall is slightly taller than the wings, has splayed corners, and includes a large, slightly battered hexagonal ventilation flue at the apex of the hipped roof. The former chapel wing is attached to the south wing and the original block.

While the interior has not been inspected, it is reported to retain its original galleried arrangement. The prison was originally designed by John Wing, and the extension by Thomas Smith included rebuilding the perimeter walls and front entrance, as well as adding the flanking front wings.