Büsingen am Hochrhein
There are no border controls between Büsingen and Switzerland because Büsingen is in a customs union with this country. The two countries agreed this in 1964 and the treaty became law in 1967. At the same time another even small part of West Germany separated from the rest of the country by land belonging to Switzerland, called Verenahof became part of the Swiss village of Büttenhardt.