the Flims Rockslide. The Posterior Rhine (, ) starts from the Paradies Glacier, near the Rheinwaldhorn. One of its tributaries, the Reno di Lei, drains the Valle di Lei on politically Italian territory. After three main valleys separated by the two gorges, Roflaschlucht and Viamala, it reaches Reichenau in Tamins. The Anterior Rhine arises from numerous source streams in the upper Surselva and flows in an easterly direction. One source is Lai da Tuma () with the Rein da Tuma, which is usually indicated as source of the Rhine, flowing through it. Into it flow tributaries from the south, some longer, some equal in length, such as the Rein da Medel, the Rein da Maighels, and the Rein da Curnera. The Cadlimo Valley in the canton of Ticino is drained by the Reno di Medel, which crosses the geomorphologic Alpine main ridge from the south. All streams in the source area are partially, sometimes completely, captured and sent to storage reservoirs for the local hydro-electric power plants. The culminating point of the Anterior Rhine's drainage basin is the Piz Russein of the Tödi massif of the Glarus Alps at above sea level. It starts with the creek Aua da Russein (lit.: "Water of the Russein"). In its lower course, the Anterior Rhine flows through a gorge named Ruinaulta (Flims Rockslide). The whole stretch of the Anterior Rhine to the Alpine Rhine confluence next to Reichenau in Tamins is accompanied by a long-distance hiking trail called Senda Sursilvana. The Posterior Rhine flows first east-northeast, then north. It flows through the three valleys named Rheinwald, Schams and Domleschg-Heinzenberg. The valleys are separated by the Rofla Gorge and Viamala Gorge. Its sources are located in the Adula Alps (Rheinwaldhorn, Rheinquellhorn, and Güferhorn). The Avers Rhine joins from the south. One of its headwaters, the Reno di Lei (stowed in the Lago di Lei), is partially located in Italy. Near Sils the Posterior Rhine is joined by the Albula, from the east, from the Albula Pass region. The Albula draws its water mainly from the Landwasser with the Dischmabach as the largest source stream, but almost as much from the Gelgia, which comes down from the Julier Pass. Numerous larger and smaller tributary rivers bear the name of the Rhine or equivalent in various Romansh idioms like Rein or Ragn. Examples: Anterior Rhine area: Rein Anteriur/Vorderrhein, Rein da Medel, Rein da Tuma, Rein da