Danube Valley Railway (Baden-Württemberg) Inzigkofen was pushed through by the German general staff, for whom the Danube Valley Railway was seen as a strategic railway in case of another war with France. Since 1901, the Danube Valley Railway, together with the Höllentalbahn (Schwarzwald), form part of the pan-regional railway link from Ulm to Freiburg im Breisgau. The Danube Valley Railway runs alongside the Danube river and crosses it several times. From Immendingen the line runs across the Upper Danube Nature Park "(Naturpark Obere Donau)", brushing up against the southern edge of the Schwäbische Alb, all the while following the course of the Danube. Between
Source of the Danube above and below Tuttlingen (see also Danube Sinkhole). As a consequence, it dries up most time of the year. Near Ulm, in terms of hydrology, the Danube gets a tributary to the Iller which is more water-rich. It even gets surpassed by the Inn. The Donaubach rises on the castle grounds near the left corner of the front face of the castle Donaueschingen in a karst spring. This karst spring has an embankment of 15 to 70 l/s and enters into the Brigach after flowing 90 meters belowground. The Brigach and the Breg become the Danube after 1.5 km. The