The Eifel-Ardennes Green Route or Eifel-Ardennes Green Road (German: Grüne Straße Eifel-Ardennen, French: Route Verte Ardennes-Eifel) is a cross-border, tourist route, about 500 kilometres long, which links the Ardennes to the Eifel. It runs from France via Belgium and Luxembourg to Germany mainly on quiet by-ways.
For seveveral years I've been seeing signs for this route (and have certainly ridden significant chunks of it, probably without realising) but I've never really bothered to look into it before now. It looks OK and would make a reasonably pleasant way to cross the Ardennes into the Eifel