An itinerary in the natural reserve of the Pierreuse, which invites the reader or the walker to a trip through the memory of Earth. It brings us through millions of years of the history of our planet that she keeps preciously engraved in the rocks. Before being a mountain, the Pierreuse was a sea, with its beaches and tropical islands.

Michel Marthaler : A geologist and professor at the University of Lausanne he teaches general geology and alpine geology. He also works on geological cartography of the Valais Alps. Passionate about mountains and their history, he published Le Cervin est-il africain? Une histoire géologique entre les Alpes et notre planète at the LEP editions.