We are wondering what are the must see sights on a short trip(week to 10 days) to Prague, Vienna and Budapest? I would prefer to only go to one castle, one art museum, and one cathedral/church and was wondering what are the top picks in each category? I realize this is subjective ,but I might get some kind of concensus. Was wondering what other highlights you experienced on this trip- parks, theatre, etc. thanks for your input.