As anywhere else, GIS is an essential tool in Galician archaeological research for examining and analysing spatial data. This is something quite clear in megalithic studies where in the last years these methods have been used for contrasting hypotheses regarding locational preferences drawn from fieldwork. As such, in this paper, a study of locational patterns of the megalithic sites located in the flattened top territories of A Serra do Barbanza (Galicia, NW Spain) is carried out. Using a site-predictive modelling approach, several environmental covariates were analysed to see their role in the distribution of mounds. Next, we study the clustering of megaliths via second-order modelling. The results obtained led us to conclude that the distribution of sites shows an aggregation at very local scales, a trend that can only be explained by intended site spacing dynamics that may have taken place over millennia. Using significance testing via Monte Carlo Simulation, the outcomes of this research allowed us to identify possible preferences regarding the selection of particular landscapes for the location of