Possible astronomical meanings of some El Molle relics near the ESO Observatory at La Silla

This paper describes a peculiar, man-made circular stone structure, associated with the ancient rock engravings that are around the site of La Silla in Chile close to the European Southern Observatory, and are attributed to the El Molle Culture. Three stones of the circle, different from all the others, were likely to pinpoint the alignment of three bright stars close to the horizon, as seen from a specific vantage point inside the structure. The El Molle was the only period in which this alignment occurred significantly close to the horizon, moreover it was only in this epoch that it could also be associated with the transition from the warm to the cold season, a period of the year which was quite important for a society that supported itself by herding and farming.