UKC

If you have only one night in Chamonix, which walk would you go on?

Looking to bivvy, ideally a spot for the night with a hammock. Turning up at 7-8pm, bags of time the next day.

Cheers

Assuming the snow has cleared by the time you go, a good contender would be starting from the Col de Montets towards Lac Blanc, bivvying anywhere along the Balcon ( perhaps in the Index area ) and continuing on to Brevent before walking down to Cham.

Cheers, I've been looking at walks on that side of the valley funnily enough. 

Or, if you have a head for heights and can cope with exposed ladders (or take a VF kit), hike up the Mer de Glace to Couvercle Refuge and Bivvy up on the shelf just before the hut beneath Aig. du Moine, looking up at Jorasses, Dent de Geant, the upper Mer de Glace and of course Mont Blanc.  Very nice, even as just a day hike.  Obviously need axe/crampons for the glacier as well (assuming that when you are there the glacier is dry).

Edit: actually, re-reading, maybe you meant you only have an evening followed by a full day, so not enough time to walk in for the bivvy at the refuge.  But you could bivvy on the way up to the train station and do the glacier-hut return in a day.

Hike to Lac du Cheserys and camp there. Best view of the Mont Blanc massif in the valley and you'll have plenty of chamois, marmots and ibex for company. Walk down to the col du montets.