One of the great things about Geocaching is its structure.
I like to call it benevolent anarchy.
There are no rules, only guidelines.
There are no rulers, only mentors.
Everyone works independently for the common good.
People Power at its Best.
So here's an anarchic cache for you.
There are no numbers, only letters.
There is no logic, only chaos.
The cache is located at:
South FE EC.CHI
East AFD GG.JGB
If you search at 34 54.716 138 41.366 you will find that the cache is not there. ABC isn't there either.
Keep working along the same lines, and you will soon realise that even if you can deduce part of the co-ordinates for yourself, and get to 120 metres from the cache, you will still need HIJ, and they are not there.
Hints
1. This cache is really a multi, but has been published as a mystery because you do need to do some research, calculations and exploration to find GZ.
Therefore, you must visit the published co-ordinates to get started.
2. You can use a car for part of the journey from WP1 to WP2, otherwise it's a long hike.
3. Each letter represents one number, but a number may be represented by more than one letter.
4. You are looking for an ammo can, it's under a rock.
5. I really want people who solved the puzzle to find the cache. Look at the gallery for what GZ looks like.
5. Look for the only quartz stone for many metres around.