Well, now this was a rather interesting promotion!
When you buy a bag of Sun World Superior grapes (look for sales at your local stores!), you can get discounts, free coupons, and more at your local zoos and aquariums.
At my small local zoo we received one free train ride AND one free carousel ride. We went on free day, brought our lunch (including our Sun World grapes that were well worth the $1.48/lb on sale at Kroger!), and just happened to go on a day when they were giving out free yogurt!
What a fun almost-free (I had to buy one more train ticket) day!
Go here to see if your area zoo or aquarium is participating.