The coordinates will take you to the junction of two walking trails
You'll see some rules about using the parks and an emergency location number...
If the location number is in the format ABCDEF(where it's a letter convert it to a number by its place in the alphabet), then your next stop is as follows:
S37 47.([28xA] -[3xB] + C)
E145 0. (DEF minus the maximum number of dogs you're allowed to walk if you're by yourself)
WP2 will take you to an oval named after a local businessman and politician from the 40s. The cache is a short distance away, as follows:
S37 47. S37 47.([number of letters on the sign, excluding dots and spaces] x 64)
E145.0.([number of words in the oval name, including abbreviations] x 100)
It is small in size so not much room for swaps unfortunately. It should be fairly obvious once you work out the coords for GZ
UPDATE AUG 2016: Hmmm... After reading the last 2 logs, I'm wondering if the sign at WP2 has been removed... I did not think to look last time I checked in on the cache... I'll go back when I get a chance, and re-do the clues to something else if it's missing. Meanwhile use the hint and check near an oval with the same name.