2019 sees the centenary of the ending of WW1 and 75 years since D;Day during WW2. The series has been placed with this, in mind.
The difficulty rating is a mix of the puzzle and the final location.
At each final there is enough room for a single car to pull over to allow room for a car to pass, if you are sensible.
The only hint for the series is at No1 for the puzzle
REPLACE the cache securly and in the same place
Now for the puzzle
Basingstoke ABCDE
Beaulieu FGHJK
North JD (H+B)(J+A).(E+F)A(A+F) West DD(H-G) HC.(H-E)(A+F)(K-A)