Where do you level up fast in Maple Story for a level 26 thief

Well where do u usually train?And how much exp do u get from the monsters there?I trained in the subway for a part of my time as a lower lvl.There is a fast respawn and monsters give fairly good exp.if not i would train in Orbis or Ludibrium.Hopefully I helped and hopefully ul find a good place to train best of luck.