Nature park
Parco Fluviale del Po e dell’Orba
Po piemontese · Torrente Orba · Bosco Marengo
Po e Orba is a historic name embracing two waterscapes: the broad Po corridor and the Torrente Orba reserve. At Bosco Marengo, irrigated meadows, hedges and riverside woods frame a lowland loop rich in birds and rural history.
One historic name, two present-day areas
Parco Fluviale del Po e dell’Orba belongs to the history of nature protection in Piedmont and remains useful when reading older maps, publications and search results. Today the main protected area along the river is Parco naturale del Po piemontese, established in 2019, while the Orba is a separate nature reserve. Both are managed by Aree Protette del Po piemontese, but they no longer form one protected area under the old name. Bosco Marengo provides the clearest starting point for an Orba visit.
Riverside woods, gravel bars and meadows
The Torrente Orba nature reserve protects 257.50 hectares in Bosco Marengo, Capriata d’Orba, Casal Cermelli and Predosa. Willows and poplars dominate the floodplain woods; oaks and robinia grow on drier ground, while dry grassland survives on gravel terraces. The reserve occupies part of the larger 506-hectare Torrente Orba SAC and SPA IT1180002, which also includes Basaluzzo and Fresonara. Fields, poplar plantations and natural habitats alternate without an obvious boundary on the ground.
The heronry and lowland birds
The Orba is one of the richest wildlife corridors in the Alessandria lowlands. The Bosco Marengo heronry supports breeding grey herons, little egrets and night herons; meadows and farmland also suit open-country birds such as corn bunting and skylark. Approaching gravel bars or woodland can disturb wildlife and nests, so use binoculars, stay on paths and watch from a distance. Orchids and other protected plants add to the botanical variety and must be left untouched.
Via dei Prati from Bosco Marengo
Via dei Prati is a 14-kilometre loop starting at the former municipal mill in Bosco Marengo, with an indicative walking time of five hours. Gravel roads, old embankments and meadows lead to the right bank of the Orba, then towards Fresonara and a section associated with the Roman Via Aemilia Scauri. The San Michele weir is a short detour outside the protected area and a useful birdwatching point. Carry water and an up-to-date route; ditches, banks and grassy tracks may be impassable after rain or floods. Do not follow the private roads encountered along the loop.
Places to discover
Open a place on the map to find your bearings. Follow permitted access routes and signs on site.
Ex mulino comunale di Bosco Marengo
Starting point for Via dei Prati, with spaces devoted to the Orba environment; check opening and services before visiting.
Open in Google Maps · Ex mulino comunale di Bosco MarengoRiva dell’Orba verso Retorto
Via dei Prati reaches the right bank opposite the hamlet of Retorto. Watch the river from the route without entering the gravel bed.
Open in Google Maps · Riva dell’Orba verso RetortoTraversa di San Michele
A short Via dei Prati detour and birdwatching point. The impoundment lies outside the protected area.
Open in Google Maps · Traversa di San MicheleCascina Merlanetta
Camper area in Casal Cermelli, a separate facility from the Bosco Marengo loop starting point.
Open in Google Maps · Cascina MerlanettaTrails in the park 4
Asti, Alessandria and surroundings
The Via dei Prati · Orba Torrent Reserve
WalkingAround the starting pointAsti, Alessandria and surroundings
Sentiero valenza-bassignana-rivarone
CyclingAround the starting pointAsti, Alessandria and surroundings
Dal Parco del Po alla Riserva Speciale del Sacro Monte di Crea
Before you visit
Does Parco Fluviale del Po e dell’Orba still exist under that name?
It is a historic designation. Today Parco naturale del Po piemontese and the Torrente Orba nature reserve are separate protected areas with the same managing authority.
Does Via dei Prati stay entirely within the reserve?
No. The loop crosses the agricultural and river landscape between Bosco Marengo, the Orba and Fresonara; the San Michele weir detour is explicitly outside the protected area.