The influence of pareidolia has often been anecdotally observed in examples of Upper Palaeolithic cave art, where topographic features of cave walls were incorporated into images. As part of a wider investigation into the visual psychology of the earliest known art, we explored three hypotheses relating to pareidolia in cases of Late Upper Palaeolithic art in Las Monedas and La Pasiega Caves (Cantabria, Spain). Deploying current research methods from visual psychology, our results support the notion that topography of cave walls played a strong role in the placement of figurative images—indicative of pareidolia influencing art making—although played a lesser role in determining whether the resulting images were relatively simple or complex. Our results also suggested that lighting conditions played little or no role in determining the form or placement of images, contrary to what has been previously assumed. We hypothesize that three ways of artist–cave interaction (‘conversations’) were at work in our sample caves and suggest a developmental scheme for these. We propose that these ‘conversations’ with caves and their surfaces may have broader implications for how we conceive of the emergence and development of art in the Palaeolithic.