Danube-Gunz interglacial age of about 900,000 to 940,000 years. There are however indications that the Uhlenberg Profile may still be placed within the Pliocene, and it would thus not correlate with the Danube-Gunz interglacial. Also uncertain is its association with the North German classification because of its position in the underlying stratum of the Gunz it could correspond to the Bavelian or the Waalian interglacial. The Danube-Gunz corresponds at least in part to the Swiss Deckenschotter glaciations. Danube-Gunz interglacial The Danube-Gunz interglacial (), Danube-Gunz warm period ("Donau-Günz-Warmzeit"), often just Danube-Gunz, or also Uhlenberg interglacial ("Uhlenberg-Warmzeit") is the second-oldest named warm period of
Danube Drava, Sava and Tisa. In Serbia, a canal network also connects to the river; the network, known as the Danube–Tisa–Danube Canals, links sections downstream. In the Austrian and German sections of the Danube, a type of flat-bottomed boat called a Zille was developed for use along the river. Zillen are still used today for fishing, ferrying, and other transport of goods and people in this area. The importance of fishing on the Danube, which was critical in the Middle Ages, has declined dramatically. Some fishermen are still active at certain points on the river, and the Danube Delta still has