Again, I was only in Austria for 4 days and did as much as we could within the time frame.  My uncle was great at showing me around Vienna, where he was from and where he grew up.  

1. Kahlenberg Mountain in Vienna has a high peak where is extremely foggy, takes about 40 minutes to drive up and it is very special because you can see the entire city of Vienna from there.   It is quiet a treat.    
2. Visit the Turkish neighborhoods that hosts the bazaars, walk around and find shop treasures like I did.  I latterly purchased 8 pairs of Turkish and Italian made shoes of leather and high quality materials, plus they were name brands, for about $10 dollars each.  It was such a fun treat for footwear aficionados like myself.  I bought some for my mother and myself.  And honestly, thinking back, I wish I spent more time in that Turkish neighborhood, because it seemed very fun, little Turkey in Vienna, Austria.
3. You must visit the Schönbrunn Palace in Hietzing, Vienna.  This is one stunning and happy palace, it is a massive yellow palace with some of the most beautiful gardens you can imagine,  it even has a labyrinth made of shrubs.  Very beautiful.    You get to walk inside the labyrinth  and find your way.  That was my first time and was quite an experience.  
4. Meet with friends for dinner or walk around Vienna, it is lively both at night and during the day. 
5. Drive outside of Vienna and experience just how vibrant green the countryside is, it is very pictoresq, beautiful mountains, valleys, small windy roads, fresh air and relaxing.