Canada do Inferno is the most important of the archaeological sites in the Côa valley. You must visit in the morning for the best view of its rock art (dating back to the Palaeolithic period), the majority of which consist of fine line incisions. Testament to continued activity over the centuries, a few engravings with religious themes dating back to the 17C are also visible, as well as works produced in the 1950s by local peasants.