The Douro (known as the Duero in Spain) rises in the mountains of north-eastern Spain, flows westwards through Castile for 580 km, then forms the Spanish-Portuguese border for 110 km, and finally flows – over the last 210 km, which are navigable – to Porto and into the Atlantic Ocean. The Douro Valley is the oldest protected wine region in the world and is famous for its port and its excellent red wines. The cultural landscape, which has been designated a UNESCO World Heritage Site, is characterised by spectacular, hand-built stone terraces along the river’s course. We began our river cruise into the Douro Valley in the coastal city of Porto. Here are a few photos: