This is the bonus cache for the Adventure Lab series "A Park for the People". Bonus numbers are given in the journal after each part of the Ad Lab, which you should feed into this formula to give you the final coordinates for this physical cache:
N52 26.ABC W002 09.DEF
Checksum: A+B+C+D+E+F=30
Not far to go, but you will need all your powers of stealth!