The village of Frasnois is at the heart of the region of lakes and waterfalls. It has four lakes: Lake Narlay, the `Petit Maclu` ,`Grand Maclu` and Lake Ilay with its small island. These last 3 lakes, in the beginning, consists of only a body of water which was filled by peat bogs over time whose flora is unique in France with its carnivorous plants.
The region is well preserved and protected. With its fauna diversity, the forests is rich in biodiversity which qualifies it to integrate the Natura 2000 site. The region is also part of the Haut Regional Natural Park. Herds of aurochs live on the shores of Lake Ilay. Wolves and lynxes also invite themselves to our forests.
Some surrounded by limestone walls, some lying in the meadows or in the heart of the forests, each of the 7 lakes has its color, its light, its character which reminds us of Scotland or Canada. The cliffs and the limestone environment also bring their characteristics. `Les Cascades du Hérisson`very well-known and appreciated, brings the natural richness of the area with all the lakes surrounding it.
It is an ideal place for all seasons especially for hikers whether they are on foot, by bike, on ski or snowshoe. You can enjoy frozen lakes and snow in winter, diversity of flowers in spring, emerald lakes in summer, and shimmering colors of leaves in fall.
The region is also rich in history. On the small island of Lake Ilay, monks had built a priory. Archaeological excavations have been carried out. And the Narlay lake keeps its legend that all the children of the village know. An old woman on Christmas Eve asked for hospitality from the villagers who refused her. In revenge, she flooded the hamlet, thus the lake appeared. On the shores of Lac de Chalain and Clairvaux, prehistoric men have lived for centuries; there are remains of lake towns that you can visit in the museums of Clairvaux.
Underground, the ground is made up of caves, the best known of which are those of the Moidons, very spectacular with their sounds and lights. The soil is also very unique at the geological level by its lesines (limestone rocks worn by the rain, causing holes).