What is wrong about exploring a really big forest that is filled with random spawns? You earn EP while you do it, you do it only if you like to explore (important) and the designer can even put a few things in there to find. (But make it impossible to document these things in internet sources!)OK, how do you make a MMO where the locations of things are not trivial to document (saying "impossible" might just be a bit much).
My first strike would be to eliminate x,y coordinates entirely. Don't show them on the map, and don't let them be available thru any in-game API/scripting. Of course, if you have a map, then you've got a de facto coordinate system: the pixels of the image of the map are arranged into a regular grid.
What next then? OK, have the map you see be different from the map I see (thus not a standard shared image). I've written before about mapping as interactive game activity.
You'd still want it possible to find your way back to the thing you found. It might need to be a case of "head up the mountain path until you see a rock shaped like a dog, then climb down the slope until [yada yada landmark landmark] and there you have it! The lost treasure of Sierra Madre!"
What about you ... how would you tackle this design challenge?