The border follows the Upper Rhine from the tripoint (Dreiländereck) with the French-Swiss and the German-Swiss borders at Basel (47°35′24″N 7°35′20″E﻿ / ﻿47.590°N 7.589°E﻿ / 47.590; 7.589), passing between Strasbourg and Offenburg. The Rhine forms the eastern border of Alsace on the French side and the western border of Baden-Württemberg on the German side.