Koy-Krilgan-kala is one of the few largest, fully excavated ancient sites of Karakalpakstan. The Fortress differs from the other monuments by its original planning. Initially, it was a round two-storied building reinforced by a double ring wall with towers and battlements. Moreover, the Koy-Krilgan-kala Fortress was surrounded by a moat 15 metres wide and 3 metres deep.

Scientists believe that originally Koy-Krilgankala was conceived as a sacred building used for astronomical observations. It may have been dedicated to the star Fomalhaut.

Early Koy-Krilgan-kala (IV–III centuries B.C.) was characterized by its monumentality, especially that of the central building, sophisticated defensive system and the presence of large storerooms. Food supplies were kept in grain pits or hums and sometimes sealed. Unfortunately, the rooms were not preserved through the ages.

However, archaeological findings of early Koy-Krilgan-kala contain art pottery, including ones with mythological scenes, censers, stepped altars and terracotta figurines, some of which depicted deities of Khorezm pantheon. During the long periods of the monument’s desolation people were still able to preserve cultural traditions. The ancient site was a place for the storage of ossuaries.

New external ring constructions (I century B.C. – IV century A.D.) contained residential compounds that were isolated from each other, separate kitchens and pantries, and rooms for religious ceremonies with various sufs and hearths.

Terracotta and alabaster statues, ornaments of ceramic jars, sculptured ceramic urns and ossuaries, fragments of wall paintings as well as stone seals discovered during the excavations represent the unique art of Ancient Khorezm. The findings also include some ancient written documents of Central Asia.