Porto has a good chocolate stop that is easy to fit into a normal walk, and a second one that deserves a trip across the river. I’d do the first while shopping in Baixa and save the Gaia visit for a day when you’re already heading to WOW.
Arcádia on Santa Catarina
Arcádia at Rua de Santa Catarina 191 is a Porto chocolate maker founded here in 1933. The traditional assortment and its Línguas de Gato are easy gifts; the port-wine bonbons are the one I’d pick for someone who wants a very Porto box. Map
Vinte Vinte at WOW, Gaia
Vinte Vinte is at WOW in Vila Nova de Gaia. Go if you’re curious about bean-to-bar chocolate or want to make chocolate part of a Gaia afternoon; don’t cross the bridge solely for a quick box if you’re short on time. Check the current opening information and whether the café or the Chocolate Story experience fits what you want. Map
Take-home versus eat-now
Bars and boxed chocolates travel better than pastries. Buy the latter when you’re ready to eat them, and don’t carry chocolate around in a warm bag all afternoon. If you’re putting jam, pâté or other paste-like gifts in hand luggage, check Porto Airport’s current liquids rules; airport screening treats some foods as liquids.
That’s enough of a chocolate itinerary: one Santa Catarina stop, or a deliberate Gaia visit. Try a piece before buying a big box, choose the flavour you actually like, and keep walking.