Wikipedia EN Altenau (Oker / Wolfenbüttel)
The Altenau (German pronunciation: [ˈaltənaʊ] ) is a small river of Lower Saxony, Germany. It rises in the Elm, northeast of Eitzum, a district of Schöppenstedt, and discharges from the right into the Oker near Halchter, a district of Wolfenbüttel.
Source: Wikipedia https://en.wikipedia.org/wiki/Altenau_(Oker)