Get on one of the boats called Moliceiros and enjoy the city from the level of canals. It’s a great way to spend about an hour in a relaxing way and to get an overview of what is where in the city. The student tickets cost about 8 euros while standard price is something about 11 to 15. Nevertheless, I believe it’s worth the cost as you will experience something unique, will hear the stories about the city, various places, architecture, cuisine, and even the economic aspect of the place.