Worth the trip alone — a UNESCO old town wedged between river and fortress cliff, Mozart's birthplace — but its Gulf secret is what lies beyond: Zell am See-Kaprun (the original Arabs' Switzerland, 90 min), Hallstatt (go very early or late), the 380m Krimml Falls, and the Grossglockner High Alpine Road. Base yourself 3-4 nights in Salzburg or Zell am See; a car unlocks everything; summer books out early.