The river Rhine in Switzerland is part of the border between parts of Austria, Germany and Switzerland. I walked most of the entire length from Basel up to the source in the Surselva valley in Winter 2016 and on previous trips.
If you have the possibility to walk somewhere else – the Rhine crosses some spectacular landscapes but it is basically a canal.
Mankind corrected the Rhine here starting in 1892. There may be some spectacular bird watching places but if you just follow the Rhine it is somehow boring. I did several parts several times and I did run my first full marathon distance along the Rhine.
Since the beginning of the second world war, the Swiss side of the Rhine is blighted with hundreds of bunkers.