Research on the Neolithic monuments and dwellings of Atlantic Europe has shown that plays of light and colour were tools for the social and symbolic construction of the world. The integration of the architectures into the surrounding landscape and the incorporation of the surrounding landscape into the architectures were an essential part of this logic. In this context, recent research in the megalithic passage grave of Dombate has evidenced an unusual physical manifestation of sunlight, which interacts with the decorated back stone. The light-and-shadow phenomenon occurs at sunrise during the period of winter solstice. In this paper we discuss the particulars of this phenomenon and we argue that sunlight when it penetrates the passage and chamber at sunrise on these dates may have dictated how the art was located and applied to the structural stone. Such differentiation seems to have had important cultural and ritual significance and encoded/embedded meaning for the tomb builders and may have implications for the consideration of the symbolic dimension of similar architectures in Atlantic Europe.