Danube once appears as the mother of Vrtra, "a dragon blocking the course of the rivers." The Finnish word for Danube is Tonava, which is most likely derived from the word for the river in Swedish and German, "Donau". Its Sámi name "Deatnu" means "Great River". It is possible that "dānu" in Scythian as in Avestan was a generic word for "river": "Dnieper" and "Dniestr", from "Danapris" and "Danastius", are presumed to continue Scythian "*dānu apara" "far river" and "*dānu nazdya-" "near river", respectively. The river was known to the ancient Greeks as the "Istros" (Ἴστρος) a borrowing from a Daco-Thracian
Danube to Kelheim, Bavaria, Germany; smaller craft can navigate further upstream to Ulm, Württemberg, Germany. About 60 of its tributaries are also navigable. Since the completion of the German Rhine–Main–Danube Canal in 1992, the river has been part of a trans-European waterway from Rotterdam on the North Sea to Sulina on the Black Sea, a distance of . In 1994 the Danube was declared one of ten Pan-European transport corridors, routes in Central and Eastern Europe that required major investment over the following ten to fifteen years. The amount of goods transported on the Danube increased to about 100 million tons