In Italy, too, the prevalence of bike routes that follow rivers is spreading after the example of middle-European routes, such as the well-known Austro-German Donauradweg; an example that is much shorter and still incomplete is the bicycle route that was created along the (*)towpath of the Sile, a small river that crosses the province of Treviso and flows into the Adriatic just north of the Venice Lagoon (in fact, the Sile once flowed directly into the lagoon, but the Doges had its course diverted to protect the lagoon from siltation).
A starting point could be the FS train station at Treviso: leaving the station turn to the right and take the street that follows along the railroad tracks; this ends at a very busy street (Via Sebastiano Venier) which, towards the right, passes under the train tracks; instead, turn left, and after a little ways you will find a bike lane on the right side of the street, cross the Sile, and after the bridge, turn right onto an unpaved path along the river which takes one to a narrow railroad underpass; this marks the beginning of Via Alzaia, which is closed to motorized traffic. You will alternate between sections that are paved and unpaved until you pass under the superhighway; immediately after that underpass, a bridge takes you across to the right bank of the Sile.
In this stretch the river is inhabited by birds of various species, the most common are coots, mallards and swans.
Shortly afterwards, the bike path continues on a wooden boardwalk, raised on stilts, as far as the village of Casièr. After Casièr the bike path continues along an unpaved section as far as Lughignano, where the towpath is interrupted; an arrow directs us onto a small paved street to the right, that in turn takes us onto the extremely busy provincial road [SP67] to Casale sul Sile.
To bypass this section of road take the local road (Via Vecchia Trevigiana) immediately ahead, and after a little ways, another local road to the left (Via delle Grazie) that brings one back, after a few hundred meters, to the same provincial road, but which we now cross in front of the modern buildings and a pharmacy; towards the left a small, local road takes us back to the towpath. The bike path continues unpaved almost all the way to Casale del Sile, where you leave the Sile for a paved road (Via Rivalta); shortly afterwards turning left (Via Vicinale Rivalta), you will pass close to various sports fields and then merge onto the road (Via Belvedere) which comes from Roncade; follow its bike lane for a few meters, and then cross the street to enter the historic center of Casale del Sile, which obviously is set along the river. Once you are through the built-up part of town you are led to a bicycle lane on the left side of the provincial road (Via S. Michele) that takes one all the way to Quarto d'Altino.
From Casale sul Sile, you could also take the road to Bonisiolo, Marcon, Dese and Favaro Veneto, which would take one back to Mestre and Venice.