Original: Hellikon  Kaiseraugst  Magden  Möhlin  Mumpf  Obermumpf  Olsberg  Rheinfelden  Schupfart  Stein  Wallbach  Wegenstetten  Zeiningen  Zuzgen      The district of Rheinfelden lies in the northwest of the canton of Aargau in Switzerland, in the Fricktal region.
Simplified: Rheinfelden is a district of the canton of Aargau in Switzerland.