Starting at Les Lindarets, near Avoriaz, and heading up to the Col de Chésery, right on the border between France and Switzerland.
The first part isn’t interesting at all, just walking up through the Avoriaz ski slopes. It gets much better once the trail leaves them for a small path that climbs properly toward the ridge.
The col sits at exactly 2,000 m. From there, the Lac Vert comes into view just below, in Switzerland (Valais), and it really is green. A quite easy hike overall, no technical difficulty.
Also tracked on Strava: