The Ciclovia Alpe Adria [Alps to Adriatic bike route], as the name suggests, connects the Austrian Alps with the Adriatic Sea, from Salzburg to Grado; for now there are relatively few sections that have been completed, but between Carnia and Tarvisio they are resurrecting the roadbed of the former Pontebbana railroad, which was decommissioned in 2001 for a new double-track alignment which for the most part now runs through a tunnel.
Here we see the section from Pontebba to Tarvisio with a side trip to Kranjska Gora, on the bike path of the Sava which is built on the roadbed of the former Habsburg [Austrian] Tarvisio-Lubiana railroad line.
Point of departure is the new train station at Tarvisio-Boscoverde: exit from the sottopassaggio [underpass] which to the north opens onto a piazzale behind the station; take the street to the right which defines one side of the piazzale and continue along a street (not cyclable) that goes under the train tracks and then climbs up to the statale [state road]. Immediately on the left you will find the beginning of the bike path which is recognizable by the yellow lines.
From here continue with a gentle upslope staying on the bike path as far as the turn-off for the Laghi di Fusine [Fusine Lakes], and then to the border with Slovenia, where the lines on the pavement change to white; the border at 850 m/2,800 feet above sea level is also the highest point and marks the divide between the watersheds of the Drava and the Sava (rivers that both end up flowing into the Danube).
After the border you descend towards Kranjska Gora, a most-beautiful Slovene village in the middle of a valley that in the winter transforms into the principal ski destination of Slovenia.
After Kranjska Gora the bike path continues to Mojstrana and Jesenice; instead, in our itinerary, we turn around and go back to the border and to Tarvisio; once we have passed the piazzale behind the train station, we find on the right a bike path that descends by way of an old railroad viaduct that bridges a spectacular gorge and there we find the Alpe Adria bike route, which, to the right, goes into Austria towards Villach, and, to the left, towards Tarvisio, Pontebba and Carnia.
On the right you can still see the clearing and the building of the old Tarvisio Centrale train station which was abandoned in 2001.
Here we choose the option to go left and immediately go through the built-up part of Tarvisio, past the former train station of Tarvisio Città, and immediately afterwards the bike path crosses a new viaduct, and then begins a gentle climb towards the saddle at Camporosso, which forms the divide between the Danube and the Po watersheds. Just before the pass you travel under a viaduct of the statale [state highway] and here we find a curious square arch through which cyclists must pass; on top of the arch there is an illuminated counter that indicates the number of cyclists that have passed underneath (I believe that the count of that day - Sunday, 31 July, around 3:00 pm - had already reached 737 because in a matter of minutes another 6 or 7 passed underneath).
After Camporosso the bike path descends on the way to Ugovizza, but it is interrupted; for some reason there is a section that could not be built on the train roadbed; we are forced to travel along on a local road, but with acceptably light traffic; this follows a loop that touches upon the village of Valbruna and then returns to the bike path.
From here to Pontebba one can pedal almost the entire way on a bike path, with some interruptions. In addition to a ford to cross a small stream and washed out area, there is an optional detour on a local road that takes one a bit higher.
Just before Pontebba the view of the torrent Fella is spectacular. About a kilometer before the train station at Pontebba, the bike path ends; one can continue along the statale as far as the station; or you can follow the bike route signs which send you along a small road that passes just north of the railroad tracks, and after going past the train station, crosses the tracks and takes you to the center of Pontebba.
This small village for many decades (from 1866 until 1918) was the border post between the Kingdom of Italy and the Austro-Hungarian Empire; after the Great War [World War I] Italy obtained the area of Tarvisio and Pontebba lost the title of frontier post.
Traces of this past are visible at the station today, which now is comprised of only two tracks, but where still visible are the vestiges of additional tracks and the underpasses of a much larger station.
Naturally this itinerary can be followed in reverse from Pontebba to Kranjska Gora and then back to Tarvisio, with a bit more climb and a bit less descent.