Multidisciplinary studies at the Idnakar (Soldyrskoye I) fortified settlement included remote sensing for the assessment of site boundaries and the evaluation of structure and thickness of the occupation layer, which is partly destroyed by plowing and erosion. Multispectral survey is shown to be more effective in locating preserved bases of defensive structures. Plant features reveal differences between the occupation layer within the site and the humified horizon outside it. Thermal imaging provides more accurate estimates of thickness and composition of the occupation layer in different areas of the site. In the inner (earliest) part, which was mainly a residential area, it is mostly thick (over 0.6 m). In the area adjoining the destroyed fortifications, the occupation layer includes a considerable amount of clay. In the central part of the fortifi ed settlement, areas of two types were revealed: thick layers containing much clay from bedrock and a thin occupation horizon. Initially, this was an economic and utility zone, and eventually it became a partly residential and partly utility area. In the area outside the fortified settlement, which at the final stage was destined for household and manufacturing activities, the layer is thin, and the bedrock is situated immediately beneath the turf. We conclude that fi ndings at Idnakar indicate the efficiency of thermal imaging in archaeological prospection based on soil characteristics.