In addition to supporting a high diversity of species, wetlands play an essential role in storing fresh water and replenishing aquifers, protecting soil erosion, protecting against flooding, maintaining water quality, controlling pollution, capturing carbon and regulating climate change, also serving as leisure and tourism areas.

The municipality of Viana do Castelo has a vast and diversified extension of wetlands in its territory. The coastal, estuarine and riverside areas present in Viana do Castelo are home to a unique biological wealth, serving as habitat for several protected species. In Veiga de São Simão and Lagoas de Vila Franca we can find, among many other animals, otters, eagles, herons and salamanders. In the zone between tides of the rocky beaches, it is possible to observe a splendor of marine living beings, such as algae, anemones and starfish, octopuses, crabs and fish.