Hahnenkammsee, lake in Heidenheim, Bavaria, Germany

Hahnenkammsee is a reservoir in the Rohrach valley southwest of Hechlingen am See, in the Hahnenkamm ridge of the Franconian Alb. It runs about 1,300 metres from north-northeast to south-southwest, covers 23 hectares and reaches 4.5 metres deep. A dam divides the northern end, where a reed belt shelters breeding waterbirds.

The Hahnenkammsee was officially inaugurated on 1 July 1977, making it the first reservoir created for the Fränkisches Seenland. It was built to replace retention areas lost during land consolidation and to promote tourism. Unlike the larger Brombachsee and Altmühlsee, it does not transfer Danube water into the Regnitz and Main river systems. In 2012 the lake underwent extensive ecological restoration.

The lake takes its name from the Hahnenkamm ridge of the Franconian Jura. Since the Altmühlsee and Brombachsee were flooded, it has drawn fewer tourists, and anglers come for pike, catfish, zander, carp, trout, grass carp and tench. A reed belt at the northern dam serves as a breeding area for water birds, and beavers have left visible gnaw marks on the eastern shore.

A beach house offers changing rooms, showers, and toilets, while nearby parking spaces ease access. A grill area, boat rentals for pedal and rowing boats, plus a 3-kilometer trail with a geological educational path make visiting straightforward.

After opening, the lake drew massive crowds with thousands of cars parking along roads and fields every weekend. This popularity faded once larger lakes were built nearby, turning it into a quiet and overlooked destination today.