The article considers the results of interdisciplinary researches of some fortified settlements in the river Cheptsa basin. Complex archaeological and geophysical researches were carried out on different sites which vary a priori in the power of a culture layer, objects of exploration and the features of layout, which are: the Kushman mound Uchkakar (a large region centre), the Vesyakar mound (agricultural and handicraft centre) and the Zabolotnovskoye mound Sadeykar (the site of the transition of the Polom and Cheptsa cultures). Main results for the Uchkakar are identifying a new structural part of the site and the features of the layout of the inner, middle and outer parts of the settlement. The drawing a composite archaeological-geophysical map on the Vesyakar has allowed estimating the tendency of changing power of the cultural layer and the layout of the site. It has also allowed identifying the border between "manufacturing" and "residential" parts. In the process of the site Sadeykar studying the borders of the settlement, which could not have been seen in the terrain, have been identified. Its regular layout has also been identified. These results make a considerable change in the strong idea of the fortified settlements of the Polom archaeological culture.