The Alsterwanderweg is beautifully landscaped and leads through the Alster Valley. For hikers and cyclists the Alsterwandeweg is suitable. There are many small branches off the main path, which are interesting for mountain bikers.
The Alstertal connects within Hamburg the four Hamburg districts located on the Alster Hummelsbüttel, Poppenbüttel, Sasel, and Wellingsbüttel. The protected valley of the Alster extends far beyond the borders of Hamburg in the north. The Alsterquelle is located about 25 kilometers north of Hamburg in Henstedt-Ulzburg in the district Rhen in Schleswig-Holstein. In the nature reserves around the headwaters of the Alster in northern and eastern Hamburg there are various protected animal and plant species, as well as rare orchids and mushrooms.
The well-signposted Alsterwanderweg extends along the river from Kayhude in Schleswig-Holstein to the Hamburg Binnenalster. The small tributaries to the Alster in the northeast of Hamburg (as in the Wohldorfer forest, in the Rodenbeker spring valley and in the Duvenstedter Brook) are small streams, so-called Beke.
Source: de.m.wikipedia.org/wiki/Alstertal