would only increase, especially without adaptation measures. Finally, The Casbah is on the list of 10 African cultural heritage sites most threatened by sea level rise. Government The city (and province) of Algiers is composed of 13 administrative districts, sub-divided into 57 communes listed below with their populations at the 1998 and 2008 Censuses: Local architecture There are many public buildings of interest, including the whole Kasbah quarter, Martyrs Square (Sahat ech-Chouhada ساحة الشهداء), the government offices (formerly the British consulate), the "Grand", "New", and Ketchaoua Mosques, the Roman Catholic cathedral of Notre Dame d'Afrique, the Bardo Museum, the old Bibliothèque Nationale d'Alger—a moorish palace built in 1799–1800 and the new National Library, built in a style reminiscent of the British Library. The main building in the Kasbah was begun in 1516 on the site of an older building, and served as the palace of the deys until the French conquest. A road has been cut through the centre of the building, the mosque turned into barracks, and the hall of audience allowed to fall into ruin. There still remain a minaret and some marble arches and columns. Traces exist of the vaults in which were stored the treasures of the dey. Djamaa el Kebir (Jamaa-el-Kebir الجامع الكبير) is the oldest mosque in Algiers. It was first built by Yusuf ibn Tashfin, but reconstructed many times. The pulpit (minbar منبر) bears an inscription showing that the building existed in 1097. The minaret was built by the sultan of Tlemcen, in 1324. The interior of the mosque is square and is divided into aisles by columns joined by Moorish arches. The New Mosque (Jamaa-el-Jedid الجامع الجديد), dating from the 17th century, is in the form of a Greek cross, surmounted by a large white cupola, with four small cupolas at the corners. The minaret is high. The interior resembles that of the Grand Mosque. The church of the Holy Trinity (built in 1870) stands at the southern end of the rue d'Isly near the site of the demolished Fort Bab Azoun باب عزون. The interior is richly decorated with various coloured marbles. Many of these marbles contain memorial inscriptions relating to the British residents (voluntary and involuntary) of Algiers from the time of John Tipton, the first English consul, in 1580 (NB Some sources give 1585). One tablet records that in 1631 two Algerine pirate crews landed in Ireland, sacked Baltimore,