One Child or Adult Ticket to Illumination: Tree Lights at The Morton Arboretum (Up to 23% Off). 38 Options. All options include the Illu-medallion, a piece of new technology, that lets visitors be a part of the interactive light display. The glowing, wearable medallion reacts to the spectacular sights and sounds along the way. Use promo code WOW25 and save even more – remember, only one code per transaction, so break them up!