Enns (river) below the Enns"). Finally, it meets the Danube at Mauthausen and the city of Enns. The Enns is a typical wild water river and draws its water from an area of more than , which is the fifth-largest in Austria. The average outflow at its mouth is . The Anisian Age in the Triassic Period of geological time is named from Anisus, the Latin name of the river Enns. In the middle of the 19th century, canals began to be built along the between Weißenbach and the Gesäuse, in order to make use of the water for agriculture and forestry.
Enns (town) Leopold V. Following the death of Ottokar IV in 1192, his Duchy of Styria — then significantly bigger than the contemporary state, reaching from present day Slovenia to Upper Austria — fell to the House of Babenberg. Thus, Enns became Austrian. As Leopold VI, Duke of Austria, endowed Enns with town privileges in 1212, it is now considered Austria's oldest town (apart from the Roman municipal status). The landmark of Enns, the belfry (Town Tower) on the Main Square, was erected between 1564 and 1568 as a bell tower, watch and clock tower during the reign of emperor Maximilian II.