To the north-east of Samarkand, at the foot of a hill Chupa-Ata in 1908, thanks to found ancient documents, the ruins of the Ulugbek Observatory were discovered by Samarkand archaeologist V.L. Vyatkin. The excavations, which lasted for many years and ended only in 1948, suggest that the found Observatory is the largest astronomical facility of the Middle Ages. “The brainchild” of Ulugbek had huge those days (1428-1429) dimensions and the cylindrical building height of 30 meters had a diameter of 46 meters. Inside, the observatory presented a deep trench curved shape with two marble walls at the edges, with carved symbols of degrees and minutes. The sextant presumably placed in the trench. Other instruments have not survived, but all seen suggest that the roof was used for astronomical measurements.
The authors of the observatory project were Ulugbek himself and his mentor Kazi-zade Rumi, the building was erected in record time, even though after the construction a year was spent for the instruments calibration.
During the work of the observatory a lot of work have been done. There are such impressive works of Ulugbek like “New astronomical tables”, “the table of geographical coordinates”, including 683 localities around the world, “Stars Directory” provides description of 1018 stars, located in the constellations, there also was determined the length of the Earth year — 365 days, 6 hours , 10 minutes and 8 seconds. But this titanic work would have been impossible without the help of brilliant scientists, astronomers and mathematicians: Dzhemshid Kashi, Kazi-zade Rumi and Ali Kushchi, headed the observatory at various times.
“The brainchild” of Ulugbek was abandoned in 1469, after his death, when the persecution of scientists started in the country.