Danube-Auen National Park on both land and water, and other invertebrates, the total number of species in Donau-Auen National Park is estimated to be at least 5,000. Danube-Auen National Park Donau-Auen National Park () covers 93 square kilometres in Vienna and Lower Austria and is one of the largest remaining floodplains of the Danube in Middle Europe. The German word Aue (variant Au) means "river island, wetland, floodplain, riparian woodland", i.e. a cultivated landscape in a riparian zone. The words Aue and Au occur in a large number of German place names—including Donau, the German word for the Danube River—and refer to forests,
Commissions of the Danube River ultimate defeat in 1945. In 1948 a Danube river conference was held, and a new treaty was adopted, putting governance of the river under commissions composed only of the riparian powers, ending more than four decades of Western European presence in the control of the important waterway. Commissions of the Danube River "See Internationalization of the Danube River for events before 1856." The Commissions of the Danube River were authorized by the Treaty of Paris (1856) after the close of the Crimean War. One of these international commissions, the most successful, was the European Commission of the Danube, or, in