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Lac Célavy is a small lake surrounding an islet in Toussaint. A hermit lives there. There is also a group of monoliths, each bearing an inscription dedicated to one of the Five Chivalric Virtues.
The name of the lake is likely a homophone for "c'est la vie", the French phrase for "that's life", or "or so it goes...".
The Five Chivalric Virtues