The "val" as a laboratory of human geography? The saga of Val d'Anniviers. The author analyses the methodological project initiated by Jean Brunhes in his study of an alpine valley considered as a «small isolated world», ideally suited to a quasi-experiment. The author looks at the variations in the text, from its first publication as an article to its inclusion in a human geography manual dating back to 1910 and republished in the middle of the 1950s, and the epistemological meaning of these differences. Finally the author attempts to interpret the rereading of this classic monograph from the viewpoint of the development of a discipline and the issue of social change.