Stay out of the Tower!
You can't just walk into the castle. To conquer the castle you must first climb up via nets. There are many ways up too, and you will have to see whether you go in through the front or the side.
Once you have entered, you can go back down by picking one of the many slides or nets. One of these slides is very exciting; the steep green slide. This is a free-fall slide in which you first fall 2 meters and then start sliding. Who dares?