In the light of the recent discussion regarding Equinoctial / Moon-based megalithic traditions I would like to point out that the south-western Iberian cromlechs (three of them featured in the Megalithic European) have been, in a recent archaeo-astronomical field study been proved to be clearly alligned on the equinoctial sunset (as seen from similar specific 'flat' decorated menhirs in all three cromlechs), and quite surely also on midwinter and midsummer sunsets from the same spot (the sunrise over the top of the Hill of Evoramonte on the opposite horizon at some of these times of the year has been well-known for some years).
In the pre-christian lunar calendar, the time when the Full Moon 'crossed paths' with the Sun (around the time of the equinox) was vital for the orientation of the cromlechs, which are on slopes facing E-SE. These measurements have survived in Christianity with the Easter Full Moon. But it is fantastic to think that the tradition goes back longer (the menhirs have been radio-carboned as mesolithic/pre-neolithic, certainly far earlier than the surrounding dolmens). Curiously, the tradition of the horse-shoe shape existed not only in the recently discovered proto-megalithic tombs but has also been recently found in paleolithic 'settlements' of the area.