Koy-Kyrylgan Kala is the ruins of the round fortification, located to the north-east of the city Turtkul.
The set of materials allow us to assume that the Koy-Kyrylgan Kala, in the initial period of its existence, was a fortified temple-tomb, where there were carried out astronomical observations.
During long state of neglect the building Koy-Kyrylgan Kala was used by craftsmen, in particular, by potters. However, the tradition was still likely to retain an idea of the monument as a large cult center. Here in the period of desolation were set ossuaries.
A large collection of art monuments were found during the excavations: terracotta and alabaster statues, reliefs on ceramic jars, ceramic urns and sculptural ossuaries, fragments of wall paintings, stone seals - all these describe an original art of ancient Khorezm. A small number of written monuments, the oldest in Central Asia, are of great interest.
Koy-Kyrylgan Kala is one of the few large, fully excavated ancient buildings, stands out sharply by its peculiar layout.
Initially it was a round in terms of two-storey building, enclosed in a circle of two walls forming a shooting gallery, divided into nine segments, arranged towers, with the entrance to the east. All construction was surrounded by ditch.
The first floor of the central building consisted of eight, covered with double arches, premises. They form two isolated complex, each of which had entry from the shooting gallery of the second floor by two ladders, placed against each other.
The second floor consists of running along the outer wall of the first floor covered shooting gallery with arrow-shaped loopholes, ringed round inside enclosed layout, subordinated to the layout of the first floor.
The whole top floor had a flat ceiling. Entrance to the central building, judging by the remnants of a ramp, was located on the east side, situated on the second floor in the outer wall of shooting gallery.
Towers of shooting gallery of the outer ring did not stand out of the line of the wall, just rose above its ceiling. Entrance of the outer ring is located on the east side. It was through one of the towers and flanked by two semi-oval towers, between which was created by entering a maze, one after the other walls. In the place, where before the entrance there was a bridge over the ditch, was a rectangular fortification, adjacent to the outer wall.
Buildings up inside the fortification around the central building was carried out gradually and was not continuous, there were stores and residential buildings too.
The hallmarks of the first period of life of Koy-Kyrylgan were the monumentality of whole construction, particularly, of the central building; the development of defensive systems and presence of large storerooms, where in the hums, sometimes sealed one, and in the grain pit there were stored food reserve.
Pottery of lower horizon is a single complex with a specific set of types of dishes, well-treated and covered with red engobe or painted with red paint.
Premises on the ground floor of the central building were not domestic. The same can be said about the premises of the second floor, which, although not preserved, but their items are found on the ground floor, such as artistically designed ceramic tableware, including mythological plots, censers, stepped altars, terracotta figurines , some of which depicted some of the Khorezm pantheon of deities, probably played a role in the commission of ritual ceremonies.