The Aussenalster — the outer Alster — is the larger sister of the Binnenalster, a roughly 160-hectare lake ringed by parks, embassies and the city's grandest 19th-century villas. The seven-and-a-half kilometre path around it is one of Hamburg's classic walks or runs, with views back over the water to the city spires.
Sailing dinghies, kayaks and stand-up paddleboards can be hired at boathouses around the perimeter — Bobby Reich on the east shore, Café Wilhelm at the southern end, and several others. In summer the lake is a small inland sea of sails on weekend afternoons. The eastern shore districts of Uhlenhorst and Harvestehude have some of the best lakeside cafés.