The north side of the Swiss Alps is drained by the Rhône, Rhine and Inn (which is part of the Danube basin) while the south side is mainly drained by the Ticino (Po basin). The rivers on the north empty into the Mediterranean, North and Black Sea, on the south the Po empty in the Adriatic Sea. The major triple watersheds in the Alps are located within the country, they are: Piz Lunghin, Witenwasserenstock and Monte Forcola. Between the Witenwasserenstock and Piz Lunghin runs the European Watershed separating the basin of the Atlantic (the North Sea) and the Mediterranean Sea (Adriatic and the Black Sea). The European watershed lies only partially on the main chain. Switzerland possesses 6% of Europe's freshwater, and is sometimes referred to as the water tower of Europe.