Jump to your heart's content! Make your next birthday extra special with us here at the Matt Griffin Y. You and 19 of your friends will have half the gym with private access to our inflatable castle bounce house for 1 hour and 30 minutes. A staff member will be present to support your party needs. Recommended for ages 3+. Upgrade to themed party for $50. (Maximum # of guests: 20 children) Additional cost is $8/child.