The megalithic sites from southwest Iberia represent one of the largest clusters of prehistoric monuments in Europe from the Neolithic and Copper Age (fifth and third millennia cal BC). Unlike other regions from western Europe, there has not been a recent effort to map the distribution of these kinds of burials across this vast territory. Therefore, this article aims to collect geographic information from three regions of southwest Iberia (Alentejo and Beira Baixa from Portugal and Extremadura from Spain) and to compare the archaeological evidence between different landscape units. We have mapped already known megaliths (ca 2000) and settlements (ca 1500) in this area. Moreover, through the interpretation of light detection and ranging (LiDAR) datasets, we have identified new walled enclosures and megaliths in the Extremadura region (Spain), the only one of the three where LiDAR data are available.The new data reveals new connections between settlements, burials and other archaeological evidence. Finally, we discuss the impact that these new data have on a new overall interpretation of megalithic landscapes from the Iberian Peninsula, stressing also the potential risks that the massive application of remote sensing can have in the production of archaeological knowledge.