With a length of almost 1233 km, the Rhine is one of the longest European rivers and the world´s most busiest inland waterway. The catchment area of the Rhine covers approximately 218,330 km2 in Switzerland, Austria, Germany, Luxembourg, France and The Netherlands. Its name probably goes back to the Indo-European word for „flow“, from which later the Latin word „rivus“ (= river) originated. The Celts called the Rhine „Rhenos“ and the Romans called it „Rhenus“
The Rhine is subdivided into the Alpine Rhine, the Bodensee (consisting of Obersee, Seerhein and Untersee), the High, Upper, Middle and Lower Rhine and the Rhine delta. Its most important tributaries are the Aare, the Maas, the Mosel, the Main and the Neckar.