
In the 17th century under the threat of an invasion of Valaisans, the shepherds of the alpine pastures of the Diablerets went to warn Lady Isabeau of the imminent risk of pillage...
Lady Isabeau was the daughter of the Lord of Pontverre, master of the castle located in the foothills of the Pic Chaussy, of which two walls are still visible today. She decided to flee in order to avoid the plundering, fires and other evils, common in that barbarous era. She took her prettiest dress, her jewellery box and left to take refuge, passing through Forclaz, through the Chavonnes forest, to the shores of its lake where she took up residence for good.
Lady Isabeau hid her jewellery box by throwing it into the middle of the lake.
Legend has it that due to her beauty and kindness, the forest sprites adopted her and turned her into a fairy. Once she had become a magic creature of the alpine pastures, she became immortal and still watches over her treasure and her friends the elves and the other sprites. Her magical powers allowed her to bring to life a white monster, the monster of Lake Chavonnes, who ate bandits and anyone who tried to retrieve the treasure from the lake.
One can see him on nights when the moon is full and delight in his bewitching song. Visitors can still see the diamonds dazzling at the bottom of the water depending on the light of the moon or of the sun (in fact, what one sees is rock formations encrusted with pyrite, a shiny mineral).
To prove the truth of this story, and to thank the shepherds of the Diablerets for having saved her from the barbarians of the time, Lady Isabeau still gives a symbolic square metre of alpine land to each young person in the town of Ormont-Dessus when they reach their majority. The town perpetuates this tradition to immortalise her lovely story. (Really true).
The above story is a synthesis of "Old Vaudois legends and tales" and of different texts written in the 19th century and at the beginning of the 20th century by various authors. Around this lake, there is an old gold mine (really registered with the Office of Mines in Lausanne) featuring, it seems, the cadaver of a dishonest miner, and rather intense and unexplainable telluric activity that frequently attracts a large number of visitors, whether they be simply curious people or mediums, with their divining rods and other pendulums.
The ancient Celts also erected a dolmen near the lake that can still be seen by hikers who walk from the lake in the direction of Forclaz.