The Ulugbek Observatory, built in the 1420s by Timurid astronomer Ulugh Beg in Samarkand, Uzbekistan, was one of the most advanced astronomical centers of its time. This three-story cylindrical structure housed a massive 40-meter sextant, enabling precise measurements of celestial bodies, including a star catalog of 1,018 stars and a stellar year calculation accurate to within a minute. Destroyed in 1449 and rediscovered in 1908, the site now features preserved underground remains and a museum showcasing its scientific legacy.