Source & Course of the Danube
Where to find the source of the Danube River?
In 15 BC Tiberius Claudius Nero (42 BC-37 AD), Roman Emperor (14-37 AD), led the campaign through the Upper Rhine Valley to the Lake Constance to force the Celts into subjugation. When the conquering Romans advanced further to the north, they discovered the headwaters of the Danube River in the modern-day Germany.
The headwaters of the Danube River are situated in the Swabian Jura in a so called Karst-Area, a unique landscape that results from the weathering of bedrock types that are soluble in water. These bedrock sediments are primarily limestone. Rainwater slowly infiltrates cracks in the limestone, dissolving the rock and enlarging the underlain openings and underlain caves. Millennia of water flowing through these landforms creates unique and sensitive ecosystems.
The Karst-Area is characterized by a subsurface network, and a lack of surface streams. The subsurface network has developed under stable conditions, consistent temperature and humidity, over thousands of years.
During the summer, when water levels of the Danube are quite low, in the Upper Basin, the river is known to sink into a series of underground channels at various points of its course, what is known as Donauversickerung. Curiously, the word translates from German as the 'disappearance of Danube'.
Obviously, this area is not navigable by boat, but where river cruises terminate at Kelhaim, curious explorers who want to follow the river all the way to the source can plan further excursions to these enticing Karst Areas.
They will find that the stream does not seep through the soil, but smoothly flows through a sequence of underground craters. This sounds almost like a fable. The stream reappears in the area further south of Aachtopf, north into Constance Lake, where it flows into the Rhine, thus linking the Black Sea with the Northern Sea. It is fascinating knowing that the two rivers come together, and that is how the nature carves out its own course.
The question where to find the genuine source of the Danube River has kept scholars busy for centuries. Is it in Donaueschingen, in St. Georgen or in Furtwangen? The fact is that all three towns are situated in the Black Forest, in the district of Schwarzwald-Baar, in Baden-Württemberg, one of the 16 federal states, in the southwestern Germany.
Today this question has definitely been settled. The Danube River begins at the confluence of the two headstreams: Breg and Brigach near Donaueschingen, in the Black Forest. It is almost at the border with Switzerland, and an area that is a known habitat and spices protection area.
In 1538 the Cosmographer Sebastian Münster (1488-1552), one of the most eminent German humanists and all-round scholars, marked the source of the Danube River with a quadrangle on a map and inscribed it with "fons danubii" (Lat.: the source of the Danube). Furthermore, he described the Donaubach as "Danuvius" and explained how Donaubach and Brigach come to form the Danube River. Therefore the extent of the Danube River started at the confluence of these rivers in this time period.
In 1544 the Geographer and Mathematician Heinricht Loriti "Glarean" (1488-1563) also confirmed that the Danube River is formed by the rivers Brigach and Breg.