The alcazaba, located in the western part of the Sabika hill, is characterized by its somewhat irregular trapezoidal plan and functioned as the central military zone of defense and surveillance of the complex, being the oldest section of construction in the Alhambra. Initially, during the 11th century during the Caliphate period, and later under the Zirid dynasty, the first Hispano-Arabic buildings were erected in response to the elevation of Granada as the capital of one of the Taifa kingdoms. Muhammad I, the first Nasrid monarch of Granada, carried out a restructuring and expansion of this fortress, fortifying its walls and erecting the main towers, while his successor, Muhammad II, completed the reconstruction of the citadel. In addition to its military function, before the construction of the Nasrid palaces, this area also served as a royal lodging.

The notable elements of the citadel are varied:

La Terraza de la Torre del Cubo, a semicircular tower built around 1586, which was later emptied in the twentieth century. Today, it is presented as a privileged terrace to contemplate the valley of the Darro and the Albaicín.

The Adarve of the north wall.

The Plaza de Armas and the terrace, also known as the tower of the Plaza de Armas. At the end of the 14th century, Ismail I built a gate under this tower for ascents from Granada, which led to a remodeling of the northern area, involving the demolition of part of the stables for its construction.

Finally, the Tower of the Hidalgos, positioned at the foot of the tower of the Vela, with an eminently defensive approach.