Riserva Naturale Del Meisino, Protected area at Po River confluence in Turin and San Mauro Torinese, Italy.

Riserva Naturale del Meisino e dell'Isolone di Bertolla is a regional nature reserve, one of 12 protected areas of the Parco del Po Torinese, created to protect the wetlands around the confluence of the Stura di Lanzo with the Po. Its Meisino park, 45 hectares on the right bank of the Po, takes its name from the Piedmontese mezzino, "middle land", the strip between the river and the plain below Superga. The reserve also includes the Colletta and Arrivore parks and the Bertolla islet, on the left bank.

The area was repeatedly flooded by the Po until 1952, when a masonry embankment was built together with the Diga del Pascolo to create a reservoir for hydroelectric power. The dam's derivation canal, running left of the inlet and rejoining the river at San Mauro Torinese, artificially created the Isolone di Bertolla in 1953. The park of Meisino was first laid out by the sixth district in 1988, and regional law no. 28 of 1990 established the special nature reserve.

The area serves as a refuge where birds and other wildlife thrive openly, and visitors come to observe nature and learn about wetland ecosystems. People spend time here watching herons, ducks, and other water birds in their natural surroundings.

The park is always open, 24 hours a day. A cycle path built by the city runs through it, and 53 urban allotment gardens lie along its inland edge near Borgata Rosa, assigned first to local residents. The pedestrian and cycle path also crosses the Sant'Anna and Costaparigi streams, which descend from the Superga hill.

Bertolla Island holds the only urban heron colony in Italy, showing how wildlife thrives in river areas alongside human activity. Many visitors miss this colony while exploring the paths, even though it ranks among the reserve's most valuable features.