At the junction of the deltas of ancient, now-dry branches of the Amu Darya and Syr Darya rivers—Akcha Darya and Zhana Darya, respectively—lie the unique monuments of the Khorezm periphery from the Late Antique period: the complex of Barak-Tam castles (the House of Barak), including Barak-Tam (almost entirely destroyed), Barak-Tam I, and Barak-Tam II. These were surveyed by members of the Khorezm Archaeological and Ethnographic Expedition (KHAEE) of the USSR Academy of Sciences, led by S.P. Tolstov, in 1945 and 1946. Both castles are relatively small in size and built from high-quality sun-dried bricks of standard Khorezmian dimensions from the antique period (40x40x10 cm). The layout and construction of the castles are similar to each other, but they do not fully adhere to the architectural traditions of classical Khorezm structures. Instead, they likely reflect the aesthetic and practical needs of the aristocracy of the semi-nomadic tribes that inhabited these territories. Their construction appears to date to the same period. Barak-Tam I has been preserved significantly better than Barak-Tam II. Sergey Pavlovich Tolstov, the head of KHAEE, dates Barak-Tam I to the turn of the 4th–5th centuries CE.

The numerous vaults in Barak-Tam I and Barak-Tam II were constructed using a method of “unsupported masonry,” necessitated by the scarcity of wood required to make centering, the curved supports for arch construction. The vault masonry begins from the end wall inside the room, to which the first row of bricks forming the arch’s contour is affixed with mortar. The next row of bricks is then attached to this contour using mortar, and the process continues row by row until the entire vault is completed. To ensure the stability of the arched brickwork, the bricks were laid not parallel but angled toward each other. This method required the insertion of a wedge between the bricks at their upper edge, so that their lower edges rested against each other through a layer of mortar. In Khorezm, fragments of ceramics were commonly used to wedge bricks in vault masonry. For example, a significant amount of ceramic fragments was discovered in the mortar between the bricks of the vaults in Toprak-Kala. The densely populated cities of the Khorezmian oases provided builders with a sufficient supply of such material.

In the Barak-Tam area, however, ceramic production appears to have been less developed. Instead, the region’s reliance on transhumant livestock farming offered builders an abundant alternative for wedge material—large animal bones. Thus, we encounter a rare construction technique in architectural practice, where bones were used for wedging bricks in the vaults.