The results of a new series of investigations on the Kashan I fortified site (Laishevo district, Republic of Tatarstan), one of the understudied cities of Volga Bulgaria, are made public in the article. In 2012, excavations were conducted in the north-eastern part of the site, adjacent to the rampart. The stratigraphy of the rampart and the cultural layer has been studied; the material obtained has been instrumental in amplifying the data about the dating and material culture of the city. On the basis of numismatic finds and ceramic materials, the dating of the Kashan I fortified settlement site from the later pre-Mongol period and the earlier Golden Horde time has been confirmed.