We were really excited to go to Porto and it didn't disappoint.
Porto is Portugal's second largest city of 1.2mio inhabitants. Set in a spectacular position above the D0uro River, the city plunges down to the river in the lower reaches of the Douro valley. If you don't like hills you may want to avoid Porto. But that would be a pity.
We did expend a fair bit of energy getting around Porto but what we were seeing and experiencing made it worthwhile. We arrived there well into the shoulder season (early October) but it was still very warm (30C +) and very busy.
We got out on the river which is a fantastic place to view the city. We'd highly recommend this. We also made it to the Jardins do Palacio de Cristal, fantastic gardens to enjoy and the views of the city from here are absolutely spectacular.
Porto is also famous for production of the fortified wine, Port. Visiting one of the famous Port houses for a tour and tasting is well worth it. All of these things should be booked ahead to avoid disappointment as places fill up quickly, even in the shoulder season.
Porto is very popular at the moment and it would be fair to say the city is struggling to keep up with visitor numbers. Don't let this put you off though as it's a special place. Just be organised.