Lac Blanc and the refuge which lies at 2352m is well worth the detour. A beautiful shade of aquamarine blue is it is one of the most recognizable landmarks of the tour de Mont Blanc and attracts many day hikers from Chamonix who take the cable car up to Flegere.
The refuge at Col De Balme 2191m that marks the border between Switzerland and France. In good weather this is an excellent spot to rest and admire the tremendous 360 views.