One of the main contributions that archaeoastronomy —assisted by rigorous methodology— can bring to studies of religious practice, particularly in Greece, is to reintegrate the visible landscape and sky with ancient religious ritual. This paper is an introduction to the approach we can use in order to better understand the role of astronomical observations in the timing of ancient Greek religious festivals and cult. The paper demonstrates that, in the case of Greece, general conclusions on the predominant eastern orientation of Greek temples do not help us improve our narrative about the role of astronomy in Greek religious practice. The Greek religious system was complex, being influenced by local traditions, identity and myths. Therefore, by combining archaeology, ancient history and classics we are able to integrate the archaeoastronomical data in the context of specific cults and thus to better understand the religious experience of the people who attended and participated in these cults.