Cairo's Al-Azhar Mosque, whose history is sometimes overlooked by visitors, is one of Egypt's most important cultural and artistic treasures,writes Samir Sobhi There is no end to the architectural gems to be found in the Gammaliya, Al-Husseiniya, Saliba and Bab Al-Wazir areas of Cairo. In fact the entire district should be viewed as an open-air museum, with every second building seeming to be at least a few centuries old. Minarets carved in stone fill the skyline, and within the surrounding mosques, schools and caravansarays there are carved wooden embellishments, stonework and stained glass that make the mind spin. Many people go to the Al-Azhar district of Cairo on a regular basis, either to relax in the company of friends in the 24-hour cafes or to introduce foreign visitors to the proud heritage of the city. However, more often than not there is little time to admire the details of all the buildings in the vicinity. Take the Al-Azhar Mosque itself, for example. The story of this building is well worth telling not only because it is one of the oldest mosques in Cairo -- only the Mosque of Amr in Masr Al-Qadima and of Ibn Tulun in Saliba are older -- but also because it has had the unusual distinction of serving as a school of learning for Islam's two rival doctrines: Shiism and Sunnism. The Mosque was originally built by the Fatimid general Jawhar Al-Siqilli (Jawhar the Sicillian) in 362 hegira (973 CE). Jawhar envisioned it as part of a royal city that would house the Caliph Al-Muizz, the fourth caliph of the Fatimid dynasty, and his administration and army. On its establishment, Al-Azhar did not just serve as a Friday mosque, but also as a school of learning as Jawhar was intent on making the Mosque the foremost school of Shiite learning in North Africa. The building of the Al-Azhar Mosque began in 359 hegira (970), almost immediately after Jawhar started building the new city of Al-Mansuria (its name was later changed to Al-Qahira). An inscription on a dome close to the mihrab commemorates the building's foundation. "In the name of God, the Merciful, the Compassionate," the inscription reads. "Built on the orders of Al-Imam Al-Muizz Li Din Allah, prince of the faithful, may God's grace be upon him and his forebears and descendants, the work being executed by his slave Jawhar Al-Kateb Al-Siqilli in the year 360 hegira" (971). Like most congregational mosques of the period, Al-Azhar was planned as an open courtyard surrounded by three arcades, the mihrab one being the biggest. The open courtyard was originally paved with stone, but at one point the flooring was redone to a decorative marble design. The stained glass windows, set in plaster moulding, are thought to be part of the original design. Egyptian rulers and their top aides renovated the Mosque extensively over the millennium that followed. In 1148 hegira (1732), prince Othman Katkhuda added a school for the blind just outside the main building and enlarged the study rooms for Syrian and Turkish students. The Tabarsiya School is a 14th-century addition by Alaaeddin Abdel-Wahed, chief of staff to sultan Al-Nasser Mohamed. It was built in 740 hegira (1339) on a piece of land that had earlier hosted the house of prince Ezzeddin Aidumur. The khedive Abbas Helmi II later turned the same school into a library for Al-Azhar. The most recent renovation of the Mosque was conducted in the late 1990s by Mohamed Ali Zeinhum, a Moscow-educated restoration expert. Zeinhum also renovated the office of Ali Pasha Mubarak in the Ministry of Education, helped restore Qasr Al-Zaafaran, and supervised the decoration of the Al-Nur Mosque in Abbasiya. He has written extensively about restoration techniques and the architecture of historic structures.