Three rivers from three directions meet at the triangle: the Danube, Inn and Ilz offer a fascinating natural spectacle. At the foot of the Niederhaus Castle complex, viewed downstream, the Ilz first flows from the left into the Danube and shortly thereafter from the right the Inn flows into the Danube.
Green, Blue and Black
The water of the Inn, which rises in the Swiss Alps, is green. The Danube, which is formed in Donaueschingen by the confluence of the Breg and Brigach, is blue-brown in colour. The water of the Ilz coming from a moor area is black. A longer stretch after the confluence, the river, which from here is still called the Danube, shows all three water colors. What is striking is how strongly the green waters of the Inn push the waters of the Danube aside.
In addition to the sometimes very large amount of water in the Inn, this is mainly due to the very different depths of the two bodies of water (Inn: 1.90 meters / Danube: 6.80 meters): The Inn flows over the Danube. It is true that the Inn carries about five percent more water than the Danube itself on an annual average; but this is mainly due to the strong flooding of the Inn when the snow melts, while the Danube has a much more constant flow of water.