Like other caches in this fair city, this one is an historical tribute to the many and varied types of windmills that pumped water from underground to enable the establishment of agriculture in our dry land. In bygone eras, windmills proliferated on the Darling Downs, and today may examples remain - some still actively in use, but many are no longer in use for pumping purposes.
Across the road from the GZ you will see a fine example of a windmill.
(The windmill itself is on private property, but cache is easily accessed from park land.)
(On car trips with the kids, along with punch buggies and pinch minis, they were punching each other every time they saw a windmill. We toned it down a bit by suggesting that they poke one another. Particularly between Toowoomba and Warwick, they poked each other prolifically!)