Switzerland, Germany, Netherlands. Partly it's the border between Germany and France
It also borders on Liechtenstein and Austria.
The river Rhine starts in canton Graubünden, Switzerland.
The Rhine begins in the Alps of Switzerland,
The Netherlands.
Switzerland.
Germany,
Liechtenstein.
The Netherlands.
The nearest river to fit your description is the River Aare
It Doesn't, The Rhine flows into the North Sea, not the Mediterranean.
The Rhine flows North to the North Sea, not the Mediterranean
Germany. Austria has the Upper Rhine on its borders, but the river does not flow through Austria.
Liechtenstein.