Archimedes had realized before anyone else how the reflective power of mirrors could intensify natural sunlight. But if the ingenious Greek inventor had used it to set Roman ships on fire during the siege of Syracuse, in a small Piedmontese village they use it to keep from being left in the dark. Viganella is a group of houses in the Antrona Valley, below the Pennine Alps. And like many towns in this valley, it suffers from a problem: the mountains above darken it for 86 days a year, from November 11 to February 2. Blame the Cresta della Colma, the 2,000-meter-high mountain behind which the sun goes into hiding for this time of winter, leaving Viganella in the dark and freezing.Not anymore, however, for a few years now: in 2006, former mayor Pierfranco Midali, with the help of architect Giacomo Bonzani and engineer Emilio Barlocco, brought the sun back to Viganella thanks to a huge reflecting mirror placed on the mountainside. An idea that the Syracusan had had more than two thousand years ago, and which modern technology has perfected, at a cost of €100,000. A 40-m² panel that, thanks to internal software, tracks sunlight and projects it onto the village. With consequent benefits for the harvest and health of its inhabitants. Viganella is the only village on the face of the Earth to have adopted such a system, which is why at the time it attracted the curiosity of journalists from all over the world. And that still attracts tourists today, while serving as an example of how technology combined with the power of nature can only benefit human beings.