We'd like the chance to see a few of the distinctive modern buildings in Porto that we've read about in the tour books. (We'll be at the Casa Musica in any case). So far, though, we've only found very expensive tours of several hours' duration. Are there other options that we're missing?
Porto has an easy to use public transport system, including the lovely old trams.
Info here:
https://www.introducingporto.com/public-transport