In 1392, the people of Martrin made a request to the Commander Pons de Panat for permission to build a defensive tower onto the side of the church to provide the inhabitants with a place of refuge during periods of war and to store their belongings so that they could be kept safe from pillage. You can also visit the Commanders grave, which is set inside the church. It is actually the tomb of Commander Pénavayre of Salèls and is carved out of fine-grained sandstone rock, which was extracted from the surrounding quarries. The lid is ornamented with crosses, coats of arms and gothic inscriptions.