I made this world when 1.9.2 came out, I haven't really played much on this world due to the fact that I thought I accidently deleted it, however this map turned out to be on my other PC so now I started playing on it again and thought I could upload it.

It's not very impressive, because I spawned like 40 blocks away from a skeleton spawner and decided to set up camp there and change the spawner into an xp farm (which is ridiculously good). so really I've just been slashing skeletons for most of the time. I will update this as the time goes on so you guys can see it evolving.

But really this XP farm yields like a minimum of 184 mobs per half hour, and that's only when the spawner spawns every 39 seconds, but since a spawner spawns 4 new mobs between 8 and 39 seconds most of the time there are hundreds of them. at least when I tested this and waited for exactly 30 minutes and then locked of the killing chamber there were 240 of them in there!