It is connected to Milan through a net of channels called navigli, which Leonardo da Vinci helped design. Near the end of its course, it creates a wide delta (with hundreds of small channels and five main ones, called Po di Maestra, Po della Pila, Po delle Tolle, Po di Gnocca and Po di Goro) at the southern part of which is Comacchio, an area famous for eels. The Po valley was the territory of Roman Cisalpine Gaul, divided into Cispadane Gaul (south of the Po) and Transpadane Gaul (north of the Po).