The Citadel, South West And South East Casemates

The Citadel's south-west and south-east casemates are military structures built around 1860, likely designed by Captain W. Crossman of the Royal Engineers, who was the general designer of The Citadel. They are constructed from rusticated Portland ashlar and feature a turf and grass roof. The casemates consist of two long sections and one shorter section along the south-west and south-east edges of the Citadel enclosure. They are supported by high earth mounds and stand above deep surrounding ditches, exposing only one face of the structure. The shorter south casemate connects the two longer units and is located next to the South Entrance.

The continuous high wall is made of rusticated ashlar with a heavy weathered coping on a deep moulding. This wall features square stacks topped with flat pyramidal cappings, a three-course plain band, and a string course with a bold cavetto-mould above stepped voussoirs leading to the main arches. The arches are segmental and supported by broad responds, with a Diocletian window above. The main opening has a prominent square porch with a tall rectangular light on the front and a heavy door beneath a transom light on the side. The porch is flanked by tall rectangular lights, although many porches were missing during the survey in May 1991.

The south-west casemate has a plain stepped wall returning at right angles to the north, leading to a heavy capping and then 35 arches. The south run contains 10 arches, while the south-east run has 17. A large segmental opening is found on the wall connecting the south-west and south casemates, leading to a flight of stairs with heavy stone balustrades. This area is flanked by paired doors beneath fanlights in rusticated surrounds, with voussoirs set within segmental arches linked at the center. Each casemate includes a deep, narrow compartment that is enclosed and vaulted in Portland stone.

This impressive series of structures encircles the main central area of The Citadel, showcasing vigorous detailing and a grand scale, while also shaping the landscape and providing views from many parts of the Island.