The tower known as the Tower of Arms or Torre de Armas was built by Muhammad I, Ibn al-Ahmar (1238-1272). It is a complex structure with an entrance way, a twist, straight stretch and two exits: one to the east which was the entrance for citizens, and that would have gone via the barbican ditch to the Tahona Gate and the Urban Organization Square, and the other to the west, only for soldiers leading to the stables.
It is one of the most complex gates in the whole Alhambra, and was the main entrance to the Alcazaba for citizens who came up from the Albayzin. It was called Torre de las Armas, Tower of Arms, because this was where those entering the Alhambra had to leave any arms or weapons. It also has an upper floor for guards and a terrace.
Midway through the 16th century this gate stopped being used as the main entrance to the Alhambra, when the Puerta de los Carros was opened converting the Justice Gate, (Puerta de la Justicia) or Esplanade, on the southern part, into the main entrance for citizens.