Altenau, Lower Saxony
| Altenau  | |
|---|---|
| Saint Nicholas Church | |
| Location of Altenau | |
| Coordinates: 51°48′10″N 10°26′44″E / 51.80278°N 10.44556°E | |
| Country | Germany | 
| State | Lower Saxony | 
| District | Goslar | 
| Town | Clausthal-Zellerfeld | 
| Subdivisions | 2 districts | 
| Area | |
|  • Total | 4.66 km2 (1.80 sq mi) | 
| Elevation | 460 m (1,510 ft) | 
| Population  (2014-12-31) | |
|  • Total | 1,758 | 
| • Density | 380/km2 (980/sq mi) | 
| Time zone | UTC+01:00 (CET) | 
| • Summer (DST) | UTC+02:00 (CEST) | 
| Postal codes | 38707 | 
| Dialling codes | 05328 | 
| Vehicle registration | GS | 
| Website | www.altenau.info | 
Altenau ([ˈaltə.naʊ] ⓘ) is a town and a former municipality in the district of Goslar, in Lower Saxony, Germany. Since 1 January 2015 it is part of the town Clausthal-Zellerfeld.
It is situated in the middle of the Harz mountains, between Clausthal-Zellerfeld and the Brocken. It was part of the former Samtgemeinde ("collective municipality") Oberharz.