Apollo, the Sun God, is one of the most prominent deities in the Ancient Greek religion. The temples and the oracles dedicated to the cult of Apollo correlate the selection of their geographical site with their special orientation, as based on ancient astronomical practices of symbolic and ritual importance. By studying the Ancient Greek temples, as for example the temples of Apollo, various researchers in the field of Archaeoastronomy, as for example, Ranieri discovered their special, non-random orientation. In this paper the special orientations of thirteen temples of Apollo are studied by the application of a novel criterion, the criterion of the platonic gnomonic factor (fgp). The majority of the temples have special arithmetic values of their corresponding fgp, and this result leads us to suggest a hypothetical application of a methodology, relating to the value of the gnomonic factor and the orientation of the temple; implemented at the time of the definition of its construction. We find that for six out of thirteen temples of Apollo, a correlation between the gnomonic factors implied by the site selected for them, their specific orientation as well as the size of their basement, exists. This analysis of the sites and orientations from a gnomonic perspective could shed light to some cultural aspects of the ancient civilizations, and their symbolic relation with the cult of this Sun God.
Keywords: platonic gnomonic factor, summer solstice, pythagorean triads, oracles.