Longterm rival to lovely Lisbon, the historic city of Porto has long drawn in visitors with its cafe culture, historic buildings, fine wines and old-Europe charm. Rows of slender buildings are squeezed together along narrow cobbled streets, washing dangles from wrought-iron balconies, and locals beat the heat of the day in alfresco cafes, sipping espresso and Douro Valley vino.

https://www.lonelyplanet.com/articles/top-things-to-do-in-porto