If you want to add a little more culture to your vacation, put Landesmuseum on your to-do list. See if guided tours are available or just wander around in your own time.
When you've spent some time at this St. Pölten museum, why not make your way to St. Polten Cathedral, Domplatz, and Sankt Polten City Hall? They're close to Landesmuseum and also a hit with tourists.