After visiting Lisbon we decided never to go back to Portugal.
We then decided to make another attempt and try Porto.
Just as well. What a difference! Not many monuments to visit but one could wonder around for days without ever getting bored. Not to mention the fabulous eating and drinking places at very reasonable prices, the local wines and, of course, the Port wine. The local people are extremely friendly and willing to help.
The Citysightseeing Tour is highly recommended: its two routes give you a full taste of the town as they take you around the old town but also through the new town as well as along the Ocean. Excellent value for money. A three days visit is the minimum recommended.