Lac du Der-Chantecoq
This artificial lake, which regulates the flow of the River Marne, is the largest in Europe (11 681 acres,1.5 times the size of Lac d'Annecy). It boasts the largest freshwater marina in France and six beaches. The nautical resort of Giffaumont makes an ideal base for trips round the lake. Its shores are dotted with ornithological outposts from which to observe the lake's feathered inhabitants. The Musée du Pays de Der also provides an interesting insight into the history and customs of this region of woods, ponds and meadows.