Inflatable Castle
Inflatable castle for sale here. Too bad the real ones weren't this inexpensive. Choose one of the smaller play castles. If you're going to get a large one, then get yourself some earplugs also. The little ones go crazy while jumping around and screaming their heads off from having too much fun. There are some four foot tall inflatable castles featuring Disney princesses. Then there are larger bounce house castles.
You might also want to check the store for an inflatable moonwalk. The inflatable castle is often called a Moonwalk.