The megalithic site o Almendres, one of the earliest public monuments of humanity, constitues the greatest set of structured menhirs in the Iberian Peninsula and certainly one of the most important in Europe. This magnific monument was initially composed by more than one hundred monoliths. Its archaelogical research allowed the detection of several construction periods through the Neolithic Period (5000-4000 bc) until got the look similar to what is nowadays presented. Ninety two menhirs of different sizes and forms currently form twwo grounds that were built oriented to different equinos directions. Around a dozen monoliths is decorated with carved drawings and relief. This was a monument with religious purposes and, probably an astronomical observatory. Is the greatest of a group of megalithic monuments in the beautiful Alentejo region.