The Orba is a river in Italy which is approximatly 70 km long from its spring in the Apennines to its confluence with the Bormida. It flows through Piedmont from South to North, until it joins with the Bormida and then the Po. The Orba flows from a mountain region, where there are nice little villages as Tiglieto, Molare and then it comes to Monferrato's hills.