I have a Kellogg’s snack pack voucher (e.g Fruit Winders, Rice Krispie Squares), how do I pre-book my ticket? To pre-book your Grown Ups Go Free ticket (i.e. buy one child ticket get one free adult ticket) click here.To pre-book your Mates Go Free ticket (i.e. buy one adult ticket get one adult ticket) click here. Related articles How do I use the National Rail Days Out Guide 2 for 1 offer? How do I redeem my Tesco Clubcard Vouchers at Warwick Castle Resort? Is there a charge for Car Parking? How do I get to you by Train? Do I receive a discount when booking online?