I want to take a souvenir photo of a Route des Grandes Alpes road sign. I'll be travelling the route north from Menton. Where is the nearest sign to Menton showing "Route des Grandes Alpes"?
I'm sure there is another one nearer to your destination, but at least in La Grave, there is a sign for sure. I pictured it personally last summer.
Here I found a German page that has picture the same road sign as I did: