Throughout history, Algerian coastal towns have been subject to various threats by sea, which has resulted in different types of fortification works. Their variety depended on their period of construction, the materials used and the genius of the place. In Algiers, these structures of fortifications vary between fortified castle, ramparts, watchtowers, etc. However, this historical legacy is, day after day, threatened with disappearance for lack of support. The Bordj Istanbul, or Turkish fort, is one of the most important, in Algiers. Before the launch of its restoration, the monument was in a state of advanced degradation caused by abandonment, vandalism and the aggression of the sea. In 2012, the operation was started by sorting the dislocated stone blocks of the building and consolidating its structure. The project has been reflected in a scientific approach that pays particular attention to the aesthetic integrity of the monument. The absence of archival documents has been surpassed by using comparative readings of the same type of forts and the stratigraphic study of the monument. His defensive function being over, it was necessary to think about his conversion. The character of the place, the architectural aspect of the building and some alterations of its material has aroused the idea of the development of the monument in a gastronomic restaurant by the sea within a private beach. Today, works have been closed and the opening of the restaurant is planned for the next summer season.