To find this cache, you must have found the 5 Adventure Lab Caches in and around Barnby-in-the-Willows and taken note of the bonus information.
The information needed for this cache is different than the information needed for the Lab Caches.
Not sure what a Lab Cache is or how to view it? That's because you need a seperate app. The app is still made by Groundspeak and it is connected to your Geocaching account. You can ONLY log a Lab Cache through this app. Wherever you download your apps from, search for Adventure Lab.
After completing each stage of the Adventure Lab, a number will be displayed that fits in to the following coordinates.
This cache contains quite a few child friendly swaps and trinkets as PennyRose123 helped fill it with things she wanted other boys and girls to enjoy.