The Belfort Gap (French: Trouée de Belfort) or Burgundian Gate (German: Burgunder Pforte) is the area of relatively flat terrain in Eastern France between the Vosges Mountains to the north and the Jura Mountains to the south. It marks the watershed between the drainage basins of the River Rhine to the east and the River Rhône to the west, part of the European Watershed between the North Sea and the Mediterranean Sea. It is also the boundary between the historic regions of Burgundy to the west and Alsace to the east, and as such has marked the Franco-German border for long periods of its history.