The autumnal high pressure system gave us clear skies with a temperature inversion with smooth air. It gave us an irresistible urge to fly through the Alps on the cold, clear day over the lightly misted valleys. We took off from Haguenau airfield north of Strasbourg on the French German border and headed south over the wide Rhine valley. I had filed a flight plan from the eastern VRP to the southern VRP in the Strasbourg CTR; but on first contact, Strasbourg Radar controller