Bad Gastein (German pronunciation: is a spa town in the St. Johann im Pongau District. Picturesquely situated in a high valley of the Hohe T…Bad Gastein (German pronunciation: is a spa town in the St. Johann im Pongau District. Picturesquely situated in a high valley of the Hohe Tauern mountain range, it is known for the Gastein waterfall and a variety of grand hotel buildings.