Full details of this series, including suggested parking and attributes, can be found at #01 Pea Soup Stroll. GC28GVV
Stage 1 – At the published co-ordinates, what are the 4 bigger numbers on the pole. Answer = JKLM. The second number is currently missing, so I have altered the formula so you don't need it.
The cache can be found at N51.04.(J+5)(L+8)(M+6) W000.11.J(L+1)(M+7)