MB : So there are no defined borders.
It's in the area, the puzzles led us to somewhere and in this somewhere there is a cache and this somewhere represents an area the size of a medium-sized town.
The notion of zone is suitable, why not, it's not a handicap to arrive at the right zone, to say to yourself it's there but nothing very precise, nor very geometric, he said ""potatoid"".
So it's not annoying but it doesn't add anything, we can completely forget about it.