Danube
"Danube" is an Old European river name derived from a Proto-Indo-European "*dānu". Other river names from the same root include the Dunaj, Dzvina/Daugava, Don, Donets, Dnieper, Dniestr, Dysna, Tana and Tuoni. In Rigvedic Sanskrit, "dānu" means "fluid, drop", in Avestan, the same word means "river". In the Rigveda, "Dānu" 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.
Source of the Danube
The Donaubach spring was considered the source of the Danube since the 15th century at least (Hartmann Schedel in his Weltchronik from 1493), but several hints suggest that this might have been true even in Roman times (Pliny the Elder in Naturalis Historia), in which the river was located in the fringes of the populated areas. The oldest cartographic depiction by Sebastian Münster from 1538 shows the Donaubach spring as a rectangular pool; in 1875, the spring was modelled into a round pool after Adolf Weinbrenner's design. In 1895 the artist Adolf Heer created a group of statues above the pool, depicting “the mother Baar” showing her "daughter", the young Danube, the way. The supposed source of the Danube is a popular tourist attraction, which is however closed until Autumn 2015 due to extensive renovation and restoration.