"Madison’s Northside" Bonus Cache.
Completion of an Adventure Lab is necessary to to find this cache. Portions of the coordinates will be revealed as you complete the five stages of “Madison’s Northside” Adventure Lab.
You must have the Adventure Lab app loaded on your smart phone.
The adventure can be found at: https://adventurelab.page.link/qRVB
Can't find the coordinates in the Adventure Lab? View the journal after completing each stage.