Belfort Gap

The Belfort Gap (French: Trouée de Belfort) or Burgundian Gate (German: Burgundische Pforte) is a plateau located between the northern rim of the Jura Mountains and the southernmost part of the Vosges in France. It marks the divide between the drainage basins of the Rhine River in the east and that of the Rhône (Doubs and Saône) in the west, part of the European Watershed between the North Sea and the Mediterranean Sea.

Its elevation varies between 345 m (1,132 ft) at its lowest and a little more than 400 m (1,300 ft). The roughly 40 km (25 mi) wide terrain corridor connects the French département of Haut-Rhin, south of the région Alsace and the Territoire de Belfort, north of the région Franche-Comté. The passage allows warm Mediterranean flows to advect northeastwards into the Upper Rhine Plain and the Middle Rhine Valley.

Lines of communication that traverse the Belfort Gap include the French Route nationale 83 and the A36 autoroute, the railway line from Paris to Basel and the planned LGV Rhin-Rhône high-speed railway, as well as the Rhône-Rhine Canal.