Belfort Pass

The total length of the passage is 45 km, the width is about 20-30 km, the height above sea level is 300-500 m ^{[1] [2]} . The bottom of the aisle is formed by clay, loess and loamy soils, which are subject to getting wet during rains, which can greatly complicate the terrain outside the road network ^{[1] [2]} . The surface of the passage over a considerable extent is covered with forests and gentle hills with a height of about 150 m ^{[1] [2]} . The steepness of the hillsides can reach average values ^{[1] [2]} .

At the northern end of the passage there are many small lakes ^{[1] [2]} . The highest water levels in the surrounding rivers are observed during the season from June to July ^{[1] [2]} .

During the Franco-Prussian war of 1870-1871, the Belfort passage became an arena of operations for units of the Prussian army that invaded France ^{[1] [2]} . By the beginning of World War II, one of the sections of the Maginot line — the Belfort fortified area — was erected to defend the Belfort passage , but, however, in June 1940 it was never used against the advancing German troops ^{[1] [2]} . In March 1945, the Belfort passage was used by units of the 1st French Army to advance to Strasbourg ^{[1] [2]} . On April 1, in the Philippsburg area, she crossed the Rhine River, creating a bridgehead from which an attack on Karlsruhe and the Swiss border followed ^{[1] [2]} .