A fun mob cycle is the high level wurms that spawn the
wurmscale cloak nameds. At 60 the ph's con blue, but you can prob just kill wurms in the area and get a cloak. The 2 are really steady xp for a shaman, I cant promise that all the wurms wont be blue at 55, but the camp would be great for a necro, because there are undead all over. Check -1300, -3000ish.. look for a big burnt spot and a giant 4 pillar tower, with a sarnak statue under it, youll find the 2 PH's among other things pathing around there. Root and camp anything you agro besides the named ph's, or xp you want to kill.
Solb Freeti Trash is my favorite xp 55+ but at 55 you could probubly have a good time in the stone spider room, since you have a pet, you could kill that fucking jerk spider.
The hole, in general will have some fun spots to camp! lots of merbs there.
That's all I can think of right now.. ill try to post more, before vellious opens this up into a ton of new spots, love this topic!