Now we are in Mértola. This town was called Myrtilis by the Romans and was an important place in southern Iberia. In the Middle Ages it was enclosed by walls, the ruins of which can still be seen today. It was conquered from the Saracens by King Sancho II. The King then gave it to the religious-military Order of Sant'Iago, who built a castle there with a Medieval keep. Perhaps the most charming aspect of the area, however, is the arrangement of the houses along the smooth, gentle slopes. The old white houses descend from the castle to the quiet waters of the River Guadiana below, where there is peaceful atmosphere, enhanced by the reflections of the white houses in the water.