This is a nice road that hugs the Guadiana river all the way from it's mouth to the town of Mértola. The road leading to Alcoutim is particularly picturesque. Castro Marim, Alcoutim and Mértola have castles worth visiting and you can even catch a small ferry into Spain at the dock in Alcoutim. Pavement is occasionally really good but most of the time it's a bit rough and bumpy.