Among the cultural monuments of Samarkand special place is given to the remains observatory , built by Ulugbek at the foot of the hill Chupan Ata.

There is little information on the structure of the observatory . It was built in 1428-1429. Ulugbek observatory was one of the biggest in the East. Its creator has held a place of honor among the outstanding astronomers of the world , and gained astronomical fame worldwide .Great Uzbek poet Alisher Navoi said about Ulugbek : " ... all of his relatives are gone , and who remembers them now? But he , Ulugbek , reached out to the sciences and accomplished a lot . " Famous astronomer Laplace named Ulugbek "the greatest observer in the history of astronomy ".

Ulugbek treatise "New gurgany table " contains an extensive theory and tables made from observations at the observatory of Ulugbek . Among the theoretical material presented various Eastern systems of chronology , the astrological theory and the theory of the planets , issues of practical astronomy.

The table of geographical coordinates of  683 different localities of the world has a great interest. Ulugbek star catalog consists of 1019 stars , divided into constellations. Each star has its own number , summarized its position in the constellation , are the coordinates - longitude and latitude, as well as to determine the magnitude stars. This star catalog was more accurate than European directories created a hundred years after the death of Ulugbek.

The observatory was equipped with the best and most advanced tools of its time . The height of the preserved part of the sextant Fakhri , located in the trench and opened in 1908 by Samarkand archaeologist Vyatkin is equal to 11 meters.
the basic constants of astronomy defines with the main instrument of the observatory  : these are the ecliptic inclination , the equinox , the length of the sidereal year , and other values . Ulugbek made observations of the stars with small armillary spheres , which re not preserved yet.

The sheer size of the sextant , a successful design and skill of Samarkand astronomers have provided highly accurate observations.
Some astronomical values were determined by Ulugbek with tremendous precision. Ulughbek determined the  length of a  year -365 days, 6 hours ,10 minutes and 8 seconds , whereas the actual value is  365 days ,6 hours ,9 minutes and 9.6 seconds.
Samarkand Ulugbek Astronomical school has a great influence on the development of astronomy in the East .
After the assassination of Ulugbek in 1449, observatory collapsed. In the XVI century, it was a heap of ruins . It was only in 1908, its remains have been found in the document of  XVII century, which points to the location of the observatory.
During the excavations of 1908-1909  was found a circular wall in a brick and part of the main instrument. In 1914-1915  at the top of the hill was cleared area with a diameter about 50 meters and arranged a vaulted roof over the trench to dig out part of the sextant .
  In 1940  it was found that the observatory was a single architectural unit; " round wall " was the remains of the outer wall of the huge three-storey building of cylindrical shape. The building had a flat roof that housed some of the astronomical instruments . The building was complex : there were large halls , rooms , corridors , passages connecting these premises, etc. The middle of the observatory held the main instrument - sextant.

During excavations in 1948 near the observatory was found with the burial of a horse, presumably attributable to the I millennium BC and owned by the people of Turkic origin.
In 1964, the observatory was opened near the memorial museum of the great astronomer . Among the exhibits are objects found during archaeological excavations , photocopies of manuscripts, murals of Ulugbek and other items that characterize the era of Ulugbek, his life and work.
Ulugbek Observatory is  one of the most interesting monuments of world importance .