The Ge 4/4^III 642 RhB-Team advertising livery locomotive on the Albula-III viadukt between Bergün and Preda

We walked down to the end of the double-track section from Preda where the more intresting part begins. I didn't know of very good summaries on the RhB on the Internet so from the few photos I've seen I knew there was an Albula-III viadukt. I presumed there had to be Albula-I and -II as well. Previously I'd visited a number of mountain railways like the Tatar-pass in Ukraine or the Tauern, Semmering and Mariazeller railways in Austria. The common is that there there are a number of bridges ofver side valleys, in some of them a few over the river of the main valley, but apart from the back-and-forth section of the Mariazellerbahn near Laubenbachmühle the railway is rather straightforward with no real tricks in track laying. It's not the case with the Albulabahn though.