Merlinfun is the official place to redeem your Kellogg's Grown Ups Go Free offer online. You will need your 10 digit offer code to hand when redeeming - you can only find this inside special promotional packs of Kellogg's cereal.
If you do not have a special promotional box with 10 digit offer code inside, you are welcome to cut out the voucher on the box and purchase your ticket on the day to receive your free entry ticket.
For full terms and conditions, including exclusion dates, please visit here. Please make sure you check opening times to avoid disappointment.