Maplestory Reboot Ice Lightning Burning Cernium Burning Royal Library Section 6 - 17850 kills/hr

By far the best "lazy" map in all of Cernium/Burning Cernium. I would recommend all players strong enough to train here 260-265, as well as familiar farmers to train here as you can train for long hours without getting burnt out. Burning Eastern Ramparts 3 has better rates, but is a little more involved. Take your pick.