Lake Hourtin and Carcans (lac d’Hourtin and de Carcans in French) is the largest of the lakes in France. It takes its name from the two municipalities along its shores: Hourtin and Carcans. It stretches from north to south, parallel to the Atlantic Ocean coast, for a length of 18 km and a maximum width of 5 km, on the Médoc peninsula. It is part of the Great Lakes of the Landes. It has been part of the Nature Reserves of France since 15 December 2009 and is managed by the National Office for Forests (ONF), an agency of the Landes in New Aquitaine.
Le Contaut, at the northern end of the lake, has in the past hosted an important seaplane base. This base subsequently became an incorporation centre for the French Navy. It is currently the subject of an extensive project to convert it into a tourist complex.
