Burj Al Ghazi Mustafa or the Great Tower is an old fortress built in the fifteenth century near the Fatimid Palace. It is considered one of the finest examples of Ottoman military architecture. It was built in 1903 over the ruins of the ancient city of Gariba on the island of Djerba. Today, the site is under the control of the Tunisian authorities. Which recognized it as a national historical monument, and was later converted into a museum that includes two mausoleums, one of Sidi Saad and the other of Ghazi Mustafa.