The possibility that archaeoastronomy could make a valid contribution to archaeology was questioned some years ago. This article suggests that this can be the case provided that, particularly in the context of prehistoric monuments, investigations do not stop at the measurement of orientations and the determination of intentionality, but move on to seeking the motivation for choosing the orientations and the meaning and effect of this choice for a prehistoric society. This approach requires different methodologies involving various conceptual schemes, skills and competences in several fields of knowledge. A case study is then presented to show how archaeoastronomy can contribute tentatively to an understanding of the mysterious end of the Temple Culture in the Maltese Islands.