After Karim Khan chose Shiraz as the capital, he ordered repairs to the city's fortifications, which included a rampart and a ditch. As part of the reinforcement work, he also commissioned the creation of a fortified residential and administrative district in the center of the city. The exact date of construction of the Citadel is uncertain, but it is surely one of the first buildings that started and completed in Shiraz under the Zand rule. The basic plan of the building is simple. It consists of an enclosure of 12,800 m², with a circular tower at each corner rising to around 14 m - slightly higher than the retaining walls. For defense purposes, the Citadel was surrounded by a ditch 4 m deep, of which no trace remains.
The walls and towers are drilled at their upper level with small arched openings. The structure rests against a stone foundation and is constructed of tight rows of narrow-fired bricks. Outside, the walls and towers are animated by the use of brick ornaments. The decorative effect is obtained using a fairly simple technique; all layers of bricks are strictly kept in horizontal alignment, and the pattern is created by varying the level of relief. Geometric patterns therefore predominate. The long walls are decorated with diamond intervals, the ends of which end in a small diamond. The relief is of a deep brick and the units are filled with rows of steps outlined in tile panels. The decoration of the towers is less sober. Here, the outermost layer of brick was used to form hollow or relief designs.
The ornamental motifs include deep bands of nested zigzags chosen in hollow relief, bands of chevrons with carefully balanced spaces with diamond patterns, bands composed of cartridges and alternating diamonds, and bands of reciprocal trefoils in hollow relief and in relief. Access to the Citadel is obtained by an entrance on the east side. Above the bridge, a remarkable plaque in colored enamel tiles, added during the Qajar rule, shows the conflict between Rostam and the White Div. The front door opens onto an octagonal anteroom. A corridor on the right connects the anteroom to a small private courtyard that once housed the service areas. Today it is neglected. On the left, the anteroom opens onto the interior territories of the Citadel. Inside, the building is simple and generally banal. All apartments are built within the retaining walls, leaving an open central courtyard 120 m long and 100 m wide. A large swimming pool and a small citrus orchard decorate the courtyard. Three small stone pools are also located opposite the north, south, and west wings of the building. The north side 6 of the building was used as a winter residence, the south side housed summer quarters and the west side has been designated for administrative purposes. The main lobby on the west side, decorated with graceful stone Moqarnas and miniature paintings with floral patterns, was once supported by two spiral stone columns trees. These columns were dismantled by Agha Mohammad Khan Qajar and brought to Tehran; two wooden columns were installed in their place.
The total area of the building is approximately 4,000 m². The apartments, six on each side, consist of adjoining rooms that overlook the courtyard through large, fretted, stained glass windows. Architects and craftsmen from all over Iran and even from India participated in the construction of the Citadel. Despite the modest appearance of the exterior facade, which is a predominant feature of Zand's buildings, the interior of the Citadel was abundantly decorated with impressive polychrome plasters and golden paintings. Beautiful scenes, made in enameled tiles, adorned the interior facade and attractively depicted attendants of the Zand period, in costumes and turbans of that time, wearing vases full of fruit. Other ornamentation: marble dados, stone columns with spiral sinks, sash stained glass windows, and inlaid doors. Unfortunately, most of the interior decorations of the building were damaged, first under the ruthless Agha Mohammad Khan Qajar and again from 1937 to 1974, when the Citadel was turned into a prison. After the Islamic Revolution, the south wing of the building caught fire and looters took advantage of it to loot part of the property - one of the doors was found several years later in a local restaurant.
The Citadel has been repaired and rebuilt several times under different rulers. The recent restoration has brought many parts of the complex returns to their original forms and layouts. The restorers, however, failed to recreate most of the decorative elements of the structure, especially its tiles. The southeast corner of the Citadel is occupied by a private bathroom belonging to the Zand family. the bath sewer system, which was later used as a prison bath, resulted in an inclination of the southeastern tower of the citadel. It was recently rebuilt so that no collapse is threatening the building right now.
Today, the Citadel houses the museum of the Zand period, including a gallery of wax figures dressed in period clothing and a lounge for temporary exhibitions.