At each stage you should be looking at the new map of the town.
All you need to do is answer the questions below and the final cache is at N 50 58.CBC W -03 13.AEA.
Enjoy your hunt!
Stage 1 A = While facing the map look right - how many vertical black drain pipes are there? Double this number.
Stage 2 B = How many hours can you park here for?
Stage 3 C = What number is written on the lamp post above the pay and display board?
Stage 4 D = How many spikes are on the gate to the right of the map?
E = D + 2
F = D - B