Hi Karen,
Welcome to the Moms Panel!
Cinderella Castle is the perfect centerpiece for the Magic Kingdom and I don't blame your friend for wanting to go inside the towers. There is a walk way through the ground floor of the Castle between the hub at the end of Main Street and Fantasyland. When your friend walks through, he'll see where the
Bibbidi Bobbidi Boutique is located. He can also see the beautiful mosaics on the walls that tells the story of Cinderella. There is a restaurant,
Cinderella's Royal Table on the second floor of the Castle. However, only Guests with dining reservations are permitted on that floor.
Cinderella Castle Suite is also located on an upper level. I would LOVE to see it! Unfortunately, they are not offering any tours of the Suite or other areas of the Castle at this time. The Suite is used for special events and giveaways. There are tons of pictures and videos on the internet to give him an idea of what the suite looks like inside - just search "Cinderella Castle Suite".
Spending the night in the Castle Suite and touring the whole castle is on my "wish" list. Guess its time for me to look for that star to wish upon. Wishing your friend many magical memories :-) Allison