The paper features the results of excavations conducted in 2017 at Isakovo hillfort located in the mouth of the Sviyaga river (right tributary of the Volga) in the buffer zone of the Island Fort of Sviyazhsk. It presents an analysis of the various ceramic complexes and stone implements discovered at the excavations. The authors determined that the initial colonization of the cape on which the settlement is located occurred in the middle of the third quarter of the 3^rd Millennium B.C. when it was inhabited by representatives of the Middle Volga variation of the Volosovo cultural and historical community of Late Eneolithic. Then, in the Late Bronze Age the territory was inhabited by representatives of an early (Atabaevo) stage of the Maklasheevka culture (14^th –12^th centuries B.C.). The construction of settlement fortifications (rampart and moat) on the cape is related to the colonization of the site by the population of the Akozino culture from the Ananyino cultural and historical area (9^th –4^th/3^rd centuries B.C., and when the latter perished, the settlement was abandoned.