Danube River
Actually, it is a mountain range, The Black Hills, which are located in western South Dakota and eastern Wyoming.
White mountain
There is no mountain that begins with W.
The Indus River starts in the Himalayas mountain range in Tibet. It flows through western Tibet, northern India, and finally into Pakistan before emptying into the Arabian Sea.
Nawarro
Jungfrau
Xolora is a mountain in Eastern Cape, South Africa
One example of a mountain that starts with the letter X is Mount Xuebaoding in China.
Alai
Vosges (?)
Anamudi and Anginda
Damavand