Behind the bridge over the Wiese in Stetten on the Weil am Rhein-Lörrach railway, the Wiese leaves German territory and flows, for its last 6 kilometres, on Swiss soil, initially through the municipality of Riehen. The German municipality of Weil am Rhein, which borders on the north-west of Riehen, does not reach all the way to the Wiese; but a short section of the Mühleteich, a branch of the river, flows through Weil am Rhein. After leaving Riehen, in the district of Kleinbasel, the river crosses under the Karlsruhe–Basel high-speed railway and, shortly thereafter, at the junction of the Swiss A2 and A3, under the A2, which becomes the German A5 motorway a little further to the north.