An integral part of the Haut-Jura Regional Natural Park, the site of the four lakes, rich in biodiversity, offers superb landscapes in all seasons. For the sake of preservation, swimming is prohibited there and it is recommended to keep dogs on a leash during walks. The waters of the Petit and Grand Maclu feed Lake Ilay. Each occupies a shallow basin carved out by the work of glaciers around 20,000 years ago. These lakes are largely surrounded by vegetation of great diversity called low marshes, megaphorbia or peat bogs. Some reedbeds also grow there. The insects flourish there thanks to the high quality of the environment and particularly the dragonflies which compete in color. The Eurasian Coot is the most faithful resident bird of these lakes. Not very discreet, it is noticed by its cries of false alarm. You may also come across the Great Crested Grebe. Narlay, Ilay, Petit and Grand Maclu are the lakes dominated by the “Pic de l’Aigle”, a crest of 993 m, from where the view extends over the entire Jura plateau. The Belvedere of the four lakes is another magnificent point of view on these lakes. Narlay lake is the deepest with its 48 m. Hiking trails allow you to discover the lakes. Ilay is also called Lac de la Motte because it has the particularity of having an island or motte. Archaeological excavations show that the motte was already inhabited in the Neolithic period.
