The article deals with the results of the archaeological works, conducted at the Baba-Ata fortified settlement in 1950s. During the study of the settlement citadel, three building horizons, connected by a well with a total length of 15 m, were identified. The lower horizon of the citadel with a central domed room, where there was a well with an underground passage, turned out to be unique in its own way. Having no similar analogues, the construction on the lower horizon gave rise to a lot of different interpretations among specialists, who considered this building as a homestead, castle, temple, sanctuary, khanqah, etc. The architectural archaeological analysis of the entire complex of sources (articles, excavation journals of expedition participants, drawings and photographs of objects under study, etc.), some of which have not been published anywhere, made it possible to give a completely different interpretation and dating of the site. The Baba-Ata fortified settlement is identified with the city of Baruket in Arabic sources, it was built by the Samanids at the beginning of the 10^th century as a border point in the northeast of the empire against the Guzes Initially, the lower horizon construction consisted of two floors. The lower – semibasement, which caused a lot of controversy, was a shelter with the possibility of evacuation through the underground passage during the hostilities and has no analogues, being a kind of only building in medieval architecture of Central Asia.