Training Grounds for Level 50-59 in MapleStory
You should level 3-4xs as fast on Retz as you would on Lorangs. Around level (Maple Story mesos) 55, you could also consider drakes meal table as a decent training spot. The exp is in general better then Retz, you will gain 85 sometimes a 240 exp times 6 a few seconds or 135 times 6 a few seconds.
The drops are also noteworthy, as wild cargos sometimes drop tobis and Drakes quite often kumbis. The only big drawback of this place is that it drains mesos. Especially with magic guard on, which is a must since cargos do around 300 damage in Maple story. Expect to earn half of what you need for the potions.
For lightning wizards, try going into the room with the roids and neohuroids in Magatia, known as C-2. It has a lot of monsters, and you can mob them to the edge of the map where there is a safe spot to zap them with lightning. We provide maple story gold for your character.