Vienna is a magical city and this is one of the highlights. As the summer house of the Hapsburgs, it was "out of town", but is now an easy subway. Take the U4 subway from the center of town Schonbrunn station, maybe 15 mintues. From there extit the station to your left and enter the gated palace grounds. Take the tour inside, its worth it. Gilded halls, art work,etc, its richly ornate. Then walk the grounds, you can easily spend a couple of hours looking at the gardens, fountains and statues. Lastly, there are great coffee shops, etc just outside the grounds. A worthwhile afternoon.

This is one of those never to be forgotten sites, that will make a trip to Austria something very special, it's not just another palace. I have seen hundreds of castles and palaces in many countries. There is no one best, because they are so different, but Schonbrunn rates high on the list. Especially if you are lucky enough to catch a musical performance in the palace ball room.