On the colorful cliffs of one the Sultauizdag eastern spurs, in the Kyzyl Kum desert there survived ruins of one of the largest castles of ancient Khorezm– Ayaz-Kala. Folk legends associate the name of the fortress of with the name of the legendary warrior-slave Ayaz. Ayaz is a Central Asian Turkic folklore hero. The semi-mythical hero, according to a legend, threw himself at an Amazon princess who lived in the Kirk-Kiz fortress. The archaeologists claim that the Ayaz-Kala fortress belongs to the II century AD – a heyday of the Kushan Empire. Stretching in a chain from East to West it was part of a system of frontiers, built to protect the oasis on the side of the desert. All fortresses were located on a visible distance from each other, probably in order to make transmission of signals of approaching enemy convenient.

Toprak-Kala, in modern Karakalpakstan, Uzbekistan, was an ancient palace city and the capital of in Chorasmia in the 2nd/3rd century CE, where wall paintings, coins and archives were discovered. Its history covers a period from the 1st to the 5th century CE. It is part of the "Fifty fortresses oasis" in modern-day Uzbekistan

This architectural site was discovered during a Khorasan expedition headed by S.P. Tolstov in 1938. All basic study of the fortress was conducted by the expedition staff. The fortress itself is not large in size and almost square in form. The study of the foundation and the structure ruins showed that the fortress was surrounded with a double vallum, and there were watchtowers in every corner of the fortress. A main street in the center of the settlement led to a temple of fire-worshippers where Zoroastrian priests were holding their sacramental rites. The residential part of the city was divided by a street into several sections with several rooms in each, where people lived by families.

Guldursun Kala fortress is dated back to the II-I centuries BC and is located in Karakalpakstan. Fortification was constructed in rectangular basis with the square of 35 hectares. Adobe walls are lined with two rows and have built-in loopholes. In V century BC the fortress was laid in ruins for unknown reasons. Approximately in the first half of XII century Guldursun Kala had been restored and turned into an important outpost of the Khorezm state. However, in the XIII century castle was again destroyed by Mongol invaders. All eight rooms of the ground floor were constructed with double arches. They were intended, apparently, for special religious purposes, and in the upper rooms were placed warehouse stocks, terracotta images of deities and apparently held religious ceremonies. Small cult terracotta, miniature vessels, ceramics decorated with mythological subjects - all found here are typical for burial items.

Ruins of thousands of fortresses are disseminated at boundless open spaces of the Khorezm steppes, but the remnants of Koy-Krylgan-kala, the Fortress of Lost Rams, are unique. The fortress was discovered by archeologists of the Khorezm expedition casually in 1938. Archeologists were surprised with the form of ancient construction, unprecedented till then in Khoresm: the powerful citadel with the remains of a protective wall was not square and or rectangular as it was used to see, but it was round. Outside, protective constructions had the form of a correct circle with the citadel in the center, it was surrounded with an external fortification with towers. The space between the central building and the wall named the "ring" appeared completely built up. The clay construction was enormous: diameter of the central building was 42 m, height in the best remained part was about 8 m, the diameter of the whole construction - about 90 m.

The Fortress represents a rather regular triangle, oriented to the cardinal directions. Its sizes are 200*170 m. A relative preservation of the Fortress can be explained by the fact that over many centuries the Fortress walls were covered with sand-drifts which contributed in a certain way to the building façade remained preserved. The Janbas-Kala walls are almost 10m high indicating the immensity of the building. Behind the outer wall there was another wall as though backing up the main one, built certainly to strengthen a defensive fortification of the Fortress. The outer wall thickening to the bottom is as wide as 1.30m and the inner one – 1m. The narrow embrasures in the Janbas-Kala outer walls also indicate its military function.

1. Duman Kala composed of three adjacent sections – a square-shaped western enclosure with corner towers; a smaller square-shaped citadel; and an irregular four-sided northern enclosure, the remains of which can no longer been seen. The western citadel is the best-preserved section, especially along its northern side, but only small section of the eastern enclosure remains