It doesn't found similar threads, also I start
First you have to be some kind of a tank (Druid, hunter's pet, lock's pet, whatever else can tank)
Second you need the quest for ursoc, the bear god
Go meet the guy on top to start the event, make sure you pick healer.
Once he is dead, you can complete your quest (use the item, not turn the quest to the npc).. go talk to the guy again and farm exp like that.
At level 76 if you are rested, he gives 26k exp (13k if not) for about 1 min of work, i grinded my whole level faster than ever, have fun grinding
And I found this a lil bit hidden:
When you kill Ursoc, you are immediately rewarded with ~25K EXP.
You can keep the completed quest, and don't need to abandon it or anything. You just go back to the quest giver and keep asking for him to be the healer.
He's really tough to beat, I would recommend two players. By myself (76 Demo Lock), I just barely survived and it took me a good 6 minutes to bring him down. With two players, you should be able to kill him in a minute or so.
(He has a little over 200,000 HP btw.)