We drove from Tende, via les Mesches and on to Casterino. On the way up from les Mesches, we stopped to offer a lift to some walkers - who turned out to be the very same people who had given us a lift the day before. We walked from above Casterino up past the refuge of Fontanalba and on to Lacs Jumeaux in time to meet the guide at 11 am. This guide (Eric) had a more scientific approach to his explanation of the rock engravings. He discussed the long distance walks over the Alps made by people in the bronze age, referring to "Oetzi", the bronze-age man whose body was found in a glacier on the Austrian-Italian border. The travel was necessary to obtain their needs such as tin and salt. On passing by Mont Bego they made their sylised marks as a kind of written record of their life. In this valley the engravings included some strange insect-like creatures a bit like scarabs.