The article provides information on building techniques and construction details of a structure and installations uncovered during the excavations at a final Chalcolithic hilltop settlement located in the Klissura locality at the village of Ilinden, in the Mesta River Valley. The available radiocarbon dates frame the occupation of the site lie between 4250 and 4000 cal. BC, and the stratigraphic evidence enables the definition of at least two construction levels. The paper focuses on the construction choices directly related to the need to adapt to or modify the local physical environment. A 3D model was made by using a combination of vector, raster and GIS software to provide a better illustration of the topographic features of the area, the place of the archaeological site and the excavated remains of buildings. The results of the excavations suggest that on the southern terrace of the elevation, there were buildings of a similar construction which reflected the specific features of the terrain. Horizontal wooden platforms and stone slabs were used for the constructions in both occupational levels. The suggested 3D reconstruction includes only the most reliable information on the structures assigned to the later period of occupation. The documented contexts find several parallels in sites with similar topography located in mountainous and semi-mountainous areas, for which the diversity of construction techniques and the use of more unusual constructions can be considered common practice.