To commemorate the 50th anniversary of the discovery of the megalithic necropolis of Petit- Chasseur in Sion (Valais, Switzerland), an international conference was organised from the 27th to the 29th of October 2011 in Sion. This book constitutes the conference proceedings. The necropolis of Petit-Chasseur still remains a key reference for the understanding of the Final Neolithic period, not only in the Alpine countries, but also throughout Europe. The scientific meeting therefore focused on the end of the Neolithic period in Valais and in the adjacent regions, on the Bell Beaker phenomenon in general, on the funerary rites of this period, and on the anthropology of megalithic societies. The conference was attended by nearly two hundred people, students, junior and senior scholars from many countries including Austria, Belgium, Spain, France, Germany, Hungary, Italy, Morocco, the Netherlands, Poland, the Czech Republic and Switzerland. The present publication includes twenty-five papers referring to the periods represented at the Petit-Chasseur necropolis, namely the end of the Neolithic, the Bell Beaker period and the beginning of the Early Bronze Age. In addition to a preface, a first group of papers - eight in total - deal directly with the Petit Chasseur Site in Sion and the end of the Neolithic in the Alps. A second group of articles constitute the section titled The Final Neolithic and the Bell Beaker Culture in Europe and beyond. This section is composed of fifteen articles presenting the results of archaeological, anthropological, botanical, and zooarchaeological analyses of Europe and Northern Africa. The conclusion drawn from the analysis is invariably the same. It is only possible to back our explicative constructions if we establish a serious dialogue with the field of cultural anthropology and if we construct a real science of the human facts, which is far from being achieved currently. The third part of this publication, which consists of two papers and is titled Societies and Megaliths, offers a discussion on megalith building societies that reflects on and develops this conclusion. All papers in English; abstracts for each paper in English and French.