Maragheh is situated on the bank of the river Sufi Chay. The Azeri-speaking population form majority in the city. It is located 130 kilometres (81 mi) from Tabriz. Maragheh is an ancient city situated in a narrow valley running nearly north and south at the eastern extremity of a well-cultivated plain opening towards Lake Urmia, which lies 30 km to the west. The town is encompassed by a high wall ruined in many places, and has four gates. Two stone bridges in good condition, said to have been constructed during the reign of Hulaku Khan (1217-1265), who made Maragheh the capital of the Ilkhanate.
Shortly thereafter it became the seat of the Church of the East Patriarch Mar Yabalaha III. The place is surrounded by extensive vineyards and orchards, all well watered by canals led from the river, and producing great quantities of fruit. The hills west of the town consist of horizontal strata of sandstone covered with irregular pieces of basalt.
One of the famous burial towers, the Gonbad-e-Kabud (Blue Tower, 1197) is decorated with decorative patterns resembling Maragheh observatory is an astronomical observatory which was established in 1259 CE by Nasir al-Din al-Tusi, an Iranian scientist and astronomer. Located in the heights west of Maragheh, East Azarbaijan province, Iran, it was once considered one of the most prestigious observatories in the world.
Hulegu Khan believed that many of his military successes were due to the advice of astronomers (who were also astrologers), especially of Nasir al-Din al-Tusi. Therefore when Tusi complained that his astronomical tables were outdated, Hulagu gave a permission to build a new observatory in a place of Tusi's choice.
According to books like Jam-e-ttavarikhe rashidi, saf-e-elhofreh, favat-o-lvafiyyat the building of the rasad khaneh started in 1259 (657 A.H.).
The library of the observatory contained 40,000 books on many subjects, related to astrology/astronomy as well as other topics. Bar-Hebraeus late in his life took residence close to the observatory in order to use the library for his studies. He has left a description of the observatory.