I know for a fact most people once they have beaten Legendary difficulty start to struggle with gaining xp with their character somewhere in game that is low risk and relatively good return....
Well I have just figured out a pretty good place to get an endless supply of monsters that grant you xp and you do not even have to move.
Like I said before this is not a cheat. I despise cheating so lets just leave it at that.
Now in Egypt (legendary) below the sphinx there is a final room that has 4 x Dark Obelisks and a whole lot of Acolytes (hovering mummy like guys that cast electrical attacks at you). My suggestion to you is kill 2 of the Obelisks and the 2 statues that attack you afterwards on each side of the room.
Leave the 2 obelisks nearest the far door. Now provided that you have plenty of potions (which most players do) you can keep killing the Acolytes that get recreated time and time again from the Obelisks.
Each Acolyte that you kill grants you XP and there is a constant endless supply of them provided you do not kill the obelisks.
Now this option is by no means going to give you any spectacular item drops or the like however it is very very low risk and the return on xp from a constant flow of monsters is a lot faster than running around in another higher risk area that will only give you a similar xp return anyways.
Its just food for thought anyways. And I have found it useful even at lower levels. Basically all the tip is around is making use of the Dark Obelisks that are around. They are an XP gift in disguise.