by air:
Basel shares its airport with Mulhouse (France) and Freiburg (Germany). It is a public law company under international law domiciled in France and the only completely bi-national airport in the world. Situated entirely on French territory, the airport has a Swiss customs sector connected to Basel via a customs road. For detailed flight information, have a look at their webpage.
by train:
Basel has two train stations straddling three countries. Basel SBB is the main one, most in Switzerland, although the section known as “Balé” SNCF is in French territory (passport control). Trams No.1 and 2 shuttle to Barfüsserplatz. Fast trains from Germany terminate at Basel SBB, but local Freiburg trains stop short at Basel Badischer Bahnhof, in a German enclave within Kleinbasel. Take tram No. 6 to the city centre.