Gailingen am Hochrhein (pronounced [ˈɡaɪlɪŋən ʔam ˈhoːxʁaɪn], lit. 'Gailingen on the High Rhine'; Low Alemannic: Gailinge am Hochrhi) is a village in the district of Konstanz in Baden-Württemberg, in southern Germany.
It is situated in a southernmost part of the region of Hegau in a unique location on the northern bank of the High Rhine, just across the border from Switzerland and close to Lake Constance. Its population is currently 3,070.
Diessenhofen (German pronunciation: [diːsn̩ˈhoːfn̩]) is a village and a municipality in Frauenfeld District in the canton of Thurgau in Switzerland. The village is situated on the south shore of the High Rhine just opposite the German town of Gailingen am Hochrhein.
The border between the modern states of Germany and Switzerland extends to 362 kilometres (225 mi), mostly following Lake Constance and the High Rhine (Hochrhein), with territories to the north mostly belonging to Germany and territories to the south mainly to Switzerland. Exceptions are the Swiss canton of Schaffhausen, the Rafzerfeld and hamlet of Nohl of the canton of Zürich, Bettingen and Riehen municipalities and part of the city of Basel in the canton of Basel-City (these regions of Switzerland all lie north of the High Rhine) and the old town of the German city of Konstanz, which is located south of the Seerhein. The canton of Schaffhausen is located almost entirely on the northern side of the High Rhine, with the exception of the southern part of the municipality of Stein am Rhein. The German municipality of Büsingen am Hochrhein is an enclave surrounded by Swiss territory.