Euas: river in eastern Afghanistan, modern Kunar.
The river Kunar in eastern Afghanistan, which is probably identical to the ancient Euas. The picture is taken from the northeast, and you are looking downstream.
In the winter of 327/326, Alexander the Great conquered the Aspasians living in this valley. Somewhere over here, he discovered the city of Nysa, where the population convinced him that they were descendants of the first followers of Dionysus. Alexander organized a bacchanal to celebrate that he had met people who knew his ancestor, and proceeded to Massaga.