The Wierzyca River is one of the left tributaries of the lower Vistula, originating in the Kashubian Lake District. Its basin covers an area of 1,603 km². The study of stronghold settlements in this region is an intriguing, yet underexplored research topic. So far, 30 strongholds have been identified (8th–13th c.). The aim of this paper is to present the results of the spatial, topographical, and functional analyses of the strongholds in the Wierzyca River basin. The research aims to determine the defensive and administrative roles of individual strongholds, as well as to examine their economic and communication networks. The study is based on GIS analyses (Viewshed, Least Cost Path, Site Catchment), spatial modelling, and the examination of natural terrain barriers such as elevations and rivers. This approach allows for a more comprehensive understanding of the factors influencing the location, their spatial significance, and the reconstruction of the of the landscape.