The Lio Maggiore Valley, which begins next to the Caglio Canal, contains around 140 hectares, making it smaller than the Dragojesolo valleys but no less interesting to visit.

In the valley, into which the Civola, Bari and San Felice canals flow, there is today extensive fish breeding activity of bass, gilt-head bream, mullet and eel.

You can admire the landscape of the fishing valleys, with their characteristic "Cavane" and "Casoni" as well as various species of animals, including some especially deserving of mention, like the European green toad and the rare beech-marten.