When you have the ability to visit (and survive) Keara's fortress, make your way to the inside part where you are required to guess the names of statues to proceed. You will reach a gate that asks if you have named all of the statues correctly. If you have NOT done so, the gate will say you guessed wrong and in doing so, it will reset / respawn every enemy in the area.
Unlike nest towers or other places that respawn enemies, these enemies still grant exp. This enables you to run in circles, killing everything you see over and over again and rake in the exp. You can rinse and repeat several times and gain several levels this way.
Eventually, you will reach a point where the exp they give isn't very much, so it will take longer to level up if you choose to continue at that point. However, when you are at that level where the exp dwindles, you should be much more powerful than when you entered.
it works as long as you are willing to tolerate the constantly diminishing exp return. The higher your level gets, the less exp the enemies give you. I do not know if it reaches a point where you get 0 exp because i too gave up and solved the puzzle after a few tries.
but overall this is a nice way to farm exp for a while
Heck no I didn't do that. I just read someones tip that if you wanted to grind that much that's how many you needed. I think it was on the gamepressure.com guide that continues to be referred to. On ly thing with that guide is that chest contents are random, not fixed. Or at least in the demo this was so. If he were to just note the locations of the chests that would be fine by me.