The recreation of an aquarium is the theme of this urban art painting in a tunnel, alluding to a campaign to sensitise the community to the preservation of the environment, being inaugurated as a way to mark World Sanitation Day (November 19th). It conveys the sensation of walking in water, with some of the native freshwater species found in the Águeda river represented in the mural, such as bogas, pikes, barbs, lamprey, otter and the kingfisher.