The Ulugh beg Madrasah（In Samarkand）

The Ulugh Bek Observatory, built in 1428-1429 by Ulugh Beg — the grandson of Timur (founder of the Timurid Empire), a renowned astronomer, scholar, poet, and philosopher, as well as ruler of Samarkand — was one of the most influential observatories in the world during the medieval period. 

The Ulug bek Madrasah was built between 1417 and 1420. Its huge entrance portal is decorated with a 15-metres arch. A mosaic panel above the arch depicts a symbolic sky with five and ten-pointed stars. The Madrasah's size is 56x81 m. Inside there is an open yard (30x40 m) with an octagonal tower in the centre. The madrasah had a platform for astronomical observations made before Ulugbek's observatory. The madrasah had fifty cells for one hundred students. Sheikh Khadja Ahrar and the poet Abdurrahman Djami were among the outstanding graduates of the madrasah. In the 18th century, the second floor and the domes on the sides were dismantled. By the 20th century most of the mosaic decoration on the facades had been lost, so the outstanding monument needed extensive restoration work. In the 20th century, the northeastern and southeastern minarets were repaired, new domes installed, the portal arch and tympan restored.

Before its destruction in 1449, the Ulugh Beg Observatory was regarded as one of the finest observatories in the Islamic world and the largest in Central Asia. Its scale surpassed previous observatories, and it boasted first - rate observational and research facilities, including giant quadrants with a radius of 40 meters, which were rare at the time. Astronomers here conducted long - term positional observations of 1018 stars, compiling the New Guragani Astronomical Tables, the first independent star catalog since Ptolemy, reaching the highest level before the 16th century.