From their sources on the western slopes of the Black Forest to their confluence with the Rhine, the Rench, Acher and Bühlot, together with their numerous tributaries, each overcome a difference in altitude of more than 700 metres. Most of this is already behind them by the time they reach the Rhine plain from the steep Black Forest valleys. The following tours roam through the wide, flat countryside with its waters, lakes, fields, meadows and forests to the Rhine crossing at Rheinau-Freistett with its barrage, ship lock and fish ladder.