Maragheh Observatory - East Azerbaijan
The construction of the Maragha Observatory commenced in 1259 under the patronage of Genghis Khan’s grandson Hūlāgū. Its director was Nasīr al-Dīn Tūsī (1201-1274), an eminent Persian mathematician, astronomer and philosopher whose reputation spread as far as China and whom Hūlāgū had appointed as one of his advisors. The observatory was in fact a scientific institute, with a main building for the observational equipment, some auxiliary buildings, and accommodation quarters. In the observatory, there was a library which is said to have contained about 400,000 volumes.