Port wine (also called Vinho do Porto, Oporto, Porto, and often simply Port) is a Portuguese wine. It comes from the Douro Valley in the northern provinces of Portugal. Porto is a fortified wine. This means that alcohol was added to it to make it stronger. Porto is a sweet wine, but comes as dry or semi-dry too. It is often served as a dessert wine. Wines which are similar to the Portuguese product called "port" are made in several countries around the world. The biggest producers are Australia, South Africa, India, Canada and the United States. However, under European Union guidelines, only the product from Portugal may be labelled as "Port". In the United States, Federal law mandates that the Portuguese-made product be labeled "Porto" or "Vinho do Porto".