If you love history and classical music, Salzburg will be a paradise for you! The birth place of Mozart, the classic arts are very lively in this city 'till this day. You'll see locals either carrying an instrument or walking to theatre classes or performances. The old town is one of the best that I've seen for seeing old churches, the birthplace of Mozart, and of course the world-famous Hohensalzburg castle (the largest intact castle in central Europe).
Insider Tip:Bring a comfortable pair of shoes before trying to walk up to the Hohensalzburg castle! Or consider taking the cable car!