The "Old Rhine" near Diepoldsau (CH) and Lustenau (A) is a waste water created by the straightening of the Rhine and forms the border between Switzerland and Austria (Vorarlberg). In the further course, the Old Rhine marks this border as far as the mouth into Lake Constance. In the Lustenau area you will find some beautiful swimming lakes and wonderful scenery that can be explored by bike. Recommendation for a rest is the restaurant "Am Rohr" near Lustenau ... very nice beer garden directly on the bike path and swimming lake. P.S. "Rohr" stands for Rhine, which can also be found in place names such as Rohrschach, Rohrspitz, etc. de.m.wikipedia.org/wiki/Alter_Rhein_(Diepoldsauer_Durchstich)