We went on a tour with Gonçalo. He is a really nice and friendly tour guide with a ton of knowledge about the city. We did the 3 hour tour which takes you through the city, along the highlights, to the river. From there it is a nice route along the water to Belem. We had a lovely morning and learned a lot about the city. Also, we got a lot of tips on things to do, places to visit and good restaurants. I would difinitely recommend going with Gonçalo or one of his staff on a tour to get to know the lovely city of Lisbon :)