The Ketchaoua Mosque (Arabic: جامع كتشاوة‎‎, Djamaa Ketchaoua) is a mosque in Algiers, the capital of Algeria. It is located at the foot of the Casbah, which was built during the Ottoman rule in the 17th century, which is a UNESCO World Heritage Site. The mosque that stands on the first of the Casbah’s many steep stairways, was logistically and symbolically the cynosure of the pre-colonial city of Algiers. The mosque is noted for its unique fusion of Moorish and Byzantine architecture.