unter 260 m|| ca. 14 km²|
| north of Herzberg am Harz in Osterode am Harz in Lower Saxony, Germany|
Confluence: of the Großer and Kleiner Lonau in Lonau
unter 340 m
Sieber → Oder → Rhume → Leine → Aller → Weser
Small towns: Herzberg am Harz
Lonau (river) Wikipedia
The Lonau is a roughly 3.5 km long (from Lonau) tributary of the Sieber. It starts in Lonau, formed by the confluence of the Große and Kleine Lonau. It then flows in a southerly (intermittently in a south-southwesterly) direction to Herzberg am Harz, where it discharges into the Sieber after the Lonau Waterfall.