The Ria de Aveiro is the lagoon system that gives Aveiro its canals, salt pans, boats, and birdlife. Beyond the postcard centre, the ria opens into a broad wetland landscape of channels, mudflats, and marshes where birdwatchers can look for waders and other water birds.
It is worth making time for the lagoon itself, especially if Aveiro otherwise feels too polished. Go by bike, boat, or on foot along the accessible edges, and aim for softer light when the water and salt flats are at their best.