When leveling up on to 100/105 there are a few levels which do not have Auto spots(AFK is your own risk please consider Posse Plugin and GTFO Macro) Here are some that fill the holes. These two spots have no Z level trouble or corridor/object/terrain navigation issues.
46 to 65~ Plane of Justice. Because its not important to squeeze the most xp per hour from your grind like the old days we have the spare time while the game plays it self.

This hallway which will see the occasional person run past doing the Trials hail at the end of the hall. You can pull two at a time and due to how beastly defiant gear will make you at this level you will sail though two mobs at once even at a 2 box combo with a2 mercs. Why i have listed 65 when these are light blue and sometimes green is because this is so safe. You will make enough back in plat to pay for even 3 box 3 merc and you should never die.
So what if someone is there.... you are extremely unlucky but this happened to me on a recent level up. Finding somewhere similar without any prep (no high levels to set you up) was hard.

Enter the steppes. This zone you will never be alone in.. at least not on my server there is always farm bots getting steppe ore. This area has some really good selling points. Non social/Non Aggro single pulls forever (at least from my experience) This area is more for level 55+ not 46+ as the mobs are about level ~60. Using a J5 Merc Tank here might make this easier if you have trouble staying alive to these mobs. I stayed at this spot till about 68 unsure about the upper limit before xp stops.
i also took a screenshot of a toon standing in the spot http://i.imgur.com/yF5YNan.jpg
give your self enough room from the rocks that you wont path onto them when trying to melee
46 to 65~ Plane of Justice. Because its not important to squeeze the most xp per hour from your grind like the old days we have the spare time while the game plays it self.

This hallway which will see the occasional person run past doing the Trials hail at the end of the hall. You can pull two at a time and due to how beastly defiant gear will make you at this level you will sail though two mobs at once even at a 2 box combo with a2 mercs. Why i have listed 65 when these are light blue and sometimes green is because this is so safe. You will make enough back in plat to pay for even 3 box 3 merc and you should never die.
So what if someone is there.... you are extremely unlucky but this happened to me on a recent level up. Finding somewhere similar without any prep (no high levels to set you up) was hard.

Enter the steppes. This zone you will never be alone in.. at least not on my server there is always farm bots getting steppe ore. This area has some really good selling points. Non social/Non Aggro single pulls forever (at least from my experience) This area is more for level 55+ not 46+ as the mobs are about level ~60. Using a J5 Merc Tank here might make this easier if you have trouble staying alive to these mobs. I stayed at this spot till about 68 unsure about the upper limit before xp stops.
i also took a screenshot of a toon standing in the spot http://i.imgur.com/yF5YNan.jpg
give your self enough room from the rocks that you wont path onto them when trying to melee

