left his native town at a young age for Baghdad to study Arabic literature and Islamic sciences at Al-Nizamiyya of Baghdad. When he reappeared in his native Shiraz he was an elderly man. Shiraz, under Atabak Abubakr Sa'd ibn Zangy (1231–1260) was enjoying an era of relative tranquility. Saadi was not only welcomed to the city but he was highly respected by the ruler and enumerated among the greats of the province. He seems to have spent the rest of his life in Shiraz. Hafiz, another famous poet and mystic was also born in Shiraz. A number of scientists also originate from Shiraz. Qutb al-Din al-Shirazi, a 13th-century astronomer, mathematician, physician, physicist and scientist was from Shiraz. In his The Limit of Accomplishment concerning Knowledge of the Heavens, he also discussed the possibility of heliocentrism. Tourism Tourist attractions in Shiraz The city is one of the key tourism sites in Iran, its cultural heritage is of global importance. The tombs of Hafiz, Saadi, and Khaju e Kermani (whose tomb is inside a mountain above the city's old Qur'an Gate). Other lesser known tombs are that of Shah Shoja' (the Mozafarid emir of Persia, and patron of Hafiz), and the Haft Tanan mausoleum, where seven Sufi mystics are buried. The Tomb of Baba Kuhi sits atop a mountain overlooking the city, and the tomb of Karim Khan Zand is at the Pars Museum of Shiraz. The oldest mosque is Atigh Jame' Mosque, which is one of the older mosques of Iran, followed by Vakil Mosque and Nasir al-Mulk mosque. The Vakil Mosque is situated west of the famous Vakil Bazaar. It covers an area of and was built in 1187 (AH) during the Zand Dynasty. On the two sides of the entrance gate there are magnificent tile-works and arches. The left and right corridors of the entrance gate are connected to the main room. The citadel of Arg of Karim Khan sits adjacent to the Vakil Bazaar and Vakil Bath at the city's central district. The most famous of houses are Zinat-ol-Moluk House and Gahavam's House, both in the old quarters of the city. The Qur'an Gate is the entrance to Shiraz. It is located near the gorge of Allah-o-Akbar and is flanked by the Baba Kuhi and Chehel Maqam mountains. The gateway once contained two hand-written Qur'āns by Sultan Ibrahim Bin Shahrukh Gurekani in an upper room, which have now