For all 45-50 hunters...
The monkey forest maps were redone, and the 2nd is godly exp. I mean godly, I was training faster there than at nightmares, which I OHKO about 70% of the time.
I'll get some pics up showing how, but pretty much there are 3 rows of platforms, and a small separation allowing you to snipe with AB, and hit all three of them at once, the only problem is that the rows are in two areas where there is a long separation vertically. Luckily there is a tele on the left that takes you to the top and bottom of the map.
Edit: Here are the pics and a mini guide to training there.
Monkey Forest II:
Pretty much the most awesome map, three areas where the lupins and zlupins spawn. The ground which have a slow spawn, and the group of platforms slightly higher than the ground, along with the next group up top.
Now, the best place to snipe and stay for till you kill most of them is the flat middle of the platforms where they overlap.
The best way to get through both of the platforms is through the map warps marked in the next pic.