answers: Danube Delta
context: suffix "-ouwe" "wetland". The modern languages spoken in the Danube basin all use names related to "Dānuvius": (); (); , (); Classified as an international waterway, it originates in the town of Donaueschingen, in the Black Forest of Germany, at the confluence of the rivers Brigach and Breg. The Danube then flows southeast for about , passing through four capital cities (Vienna, Bratislava, Budapest and Belgrade) before emptying into the Black Sea via the Danube Delta in Romania and Ukraine. Once a long-standing frontier of the Roman Empire, the river passes through or touches the borders of 10 countries: Romania </s> reflection of the ancient one. Since the Swabian Alb is largely shaped of porous limestone, and since the Rhine's level is much lower than the Danube's, today subsurface rivers carry much water from the Danube to the Rhine. On many days in the summer, when the Danube carries little water, it completely oozes away noisily into these underground channels at two locations in the Swabian Alp, which are referred to as the Donauversickerung (Danube Sink). Most of this water resurfaces only south at the Aachtopf, Germany's wellspring with the highest flow, an average of , north of Lake Constance—thus feeding </s> what is the spring of the Danube also interested the oceanographer Jacques Cousteau, who in 1987 filmed a documentary about the Danube around St. Martin's Church. For centuries, the two cities Furtwangen and Donaueschingen competed for an official status which declares their own source as the official source of the Danube. The city Furtwangen is located along the upper river Breg, while the city Donaueschingen is located at the symbolic source of the Danube. At times, the issue even involves the government of Baden-Württemberg. After the city council Donaueschingen intervened in 1981, for example, the Ministry of the Interior in
question: where is the mouth of the danube river located