There are 2 cache here - a traditional and the start of a letterbox. Use numbers on the sign for this letterbox.
The final is:
N3A 16.ZZB W84 24.XCZ
There are dates on the sign: where the date is in the form month / day
A / BC to X / Y Z = Y/2
Summ check A+B+C+X+Y= 23