For determining the position of Strongholds, you can use Amidst.
However, what is your plan? Placing PokéCube villages on this "ring" only?
Amidst looks awesome! Thank you for the tidbit.
I don't know a lot about Minecraft yet, strongholds were the only example of something I knew of that changed from distance from spawn. PokeMob levels seem to as well, though I don't think those are the same mechanics. My plan was to get some random gen gyms in for me to explore and find. Though the pokemon level of the gym leader problem wouldn't match that of the player.