Cairo's citadel, one of the Egyptian capital's most prominent landmarks, opened another wing housing two semi-circular towers to the public on Sunday, to expand the country's tourist attractions. One of the world's biggest mediaeval citadels, the Citadel of Cairo dates back to about 1176 A.D. when construction began under the Muslim military commander Salah al-Din al-Ayyubi, who later went on to conquer Jerusalem from the Crusaders in 1187 A.D. The fortress, also known as the Saladin Citadel and which towers over Cairo, was the base of Egypt's government for over 700 years.