Exploring Alcácer do Sal is almost like entering the Alentejo through the great Atlantic road, which is the River Sado. A splendid riverside settlement since prehistoric times, its importance grew in the Roman period, as the first port of access to the whole empire. Built in mediaeval times, the castle is one of the most important symbols of the Christian reconquest and of the installation of the order of Saint James of the Sword. The surrounding fields are today immense rice paddies; this cereal crop has made its mark on the landscape, gastronomy and the natural habitats for the fauna and flora.