The Citadel of Saladin, also known as the Citadel of the Mountain, is located on Mount Mokattam in Cairo. Construction began during the reign of Saladin (Salah al-Din Al-Ayyubi) but was not completed in his lifetime; it was finished by Sultan Al-Kamil. 

The citadel served as the royal residence of Egypt's rulers until the era of Khedive Ismail. 

It has witnessed significant historical events during the Ayyubid and Mamluk periods, as well as during the French campaign in Egypt. 

The citadel features several gates and towers, including the Clock Tower. It also houses multiple palaces, such as the Jewel Palace, the Ablaq Palace, and the Haram Palace. 

Notable landmarks within the citadel include the Mosque and Madrasa of Al-Nasir Qalawun and the magnificent Mosque of Muhammad Ali, one of the most luxurious mosques in Egypt, where annual celebrations are held. 

Visitors can explore the citadel, its mosques, and enjoy a panoramic view of Cairo from atop Mount Mokattam.