The fortresses were part of a series of forts located at the edge of the Kyzyl-Kum Desert, which provided defense against raids by nomads and the Kipchak-speaking nomadic tribes of the Syr-Darya delta. Ayaz Kala is easily accessible by vehicle from Khiva and Urgench via Biruni and Buston. It is about 70 km from Urgench on a good bitumen road. It is about 32 km from Ayaz Kala to Toprak Kala.
During the 6th to 8th cent. AD Khorezm was ruled by the Afrighid dynasty of Khorezmshahs. At this time the "dihqans", a new class of feudal landowners came into existence. They were descendants of the ancient nobility, courtiers or soldiers who had been rewarded for military services. Their agricultural estates were called "rustaq". They lived in "donjons", small square forts surrounded by a defensive wall. An important example calles Yakke Parsan which is situated 10 Km south of Ayaz Kala.
The fort has residential quarters, ceremonial halls with ceilings supported by multiple columns and a fire temple, luxuriously decorated with wall paintings. This building seems to have been the residence of an feudal lord loyal to the Khorezmshah. The building was built in the 4th cent. AD and destroyed by two separate fires. It was in use during the 6th and 7th cent AD as a domestic dwelling. Ayaz Kala II seems the have been the centre of a small rural community and might have been in use until the Mongol invasion in the 13th cent. The best view of the site is from the top of Ayaz Kala I. The best pictures of Ayaz Kala I and II are taken at sunset.
Ayaz Kala III is a fortified garrison dating from the 1st to 2nd cent. AD. The monumental building in the north east corner may have been founded in the 5th or 4th cent. BC: The site covers an area of about 5 hectares. The enclosure wall is one of the largest fortresses in Karalpakstan. It has the shape of a parallelogram with sides 260 m and 180 m long. The structure of the external wall is similar to that of Ayaz Kala 1. The external walls are 7.5m wide. The circular watch towers are approx. 8 m in height. The fortress was built with paksha "cob" and masonry (adobe blocks). The entrance to the fortress on the western side consists of an S-Shaped extension of the external wall. The interior of the fortress is largely empty.
The monumental buildings in the north east corner cover an area of 2,400 square meters. The building has 40 rooms divided into 4 groups by 2 central corridors. There are remains of a narrow corridor on three sides of the buildings. The southern and eastern walls have square watch towers dimension about 2m x 2m. It is supposed that Ayaz Kala III was used in Kushan times as a garrison or as a ruler's residence and refuge for the local farming population and that a small force used Ayaz Kala I as a lookout post. The remains of many farm dwellings and evidence of vineyards were found around walls of the fortress.