Nu’roga is an level 80 instance in the Fens of Nathsar. The instance is great for farming plat at level 90 + and a run can give you 10-20 plat at least. To get to Nu’roga, head to the goblin area in northwestern Fens of Nathsar (see the map below for more details.) A run through here at level 90 can take anywhere from 20 min to 1 hour depending on how much of the zone you skip.
To get the chest with the plat in it at the end, you will need to kill the ? wisp monster on the third level. Click the ? to try to gather it, then kill it. The ? will then drop the key needed for the chest at the end.
One important thing to keep in mind here is Bricktop. Bricktop will buff and heal himself and will need to be dispelled, so if you can’t dispel, get a mercenary that can. However you should suspend your mercenary before the chest at the end so that they don’t take half the plat.
Now once you are done, head to the top and grab the chest. The chest will drop 10 + plat, so combined with all the stuff you got from farming the instance you should have made quite a few platinum.