Viana do Castelo is served by several small supermarkets, or supermarkets of various sizes, where you can make all kinds of shopping. In addition to conventional supermarkets, you can buy fruit and vegetables from local producers in the municipal market, with the best days being Wednesdays and Fridays in the morning.
About 150m from the LINK you can even find a mini market, where you will be attended by a very friendly lady, always ready to help and with lots of stories to tell.