Herphah:
Do you want to know the instanced dungeons recommendable for each level?
Well, do you see the Kartia's Researcher over there? The researcher can send you into the Kartia's Labyrinth. From level 85 to level 90 and up to level 95, you can enter there alone or with other colleagues.
For level 99 or higher, I recommend the Nightmare Kamaloka You can enter through Captain Kurtiz. Or, you can go to the Town of Gludio and ask Refugee Neti about the Ashen Shadow Revolutionaries. It's a little far, but I recommend Mystic Tavern in the underground Gainak.
If you are level 100, raid the Command Post in the Atelia Fortress. If your level is higher, ask Agent Georgio at the top of the stairs to teleport you to the Altar of Shilen.
Are you above level 103? If som I recommend you to create a coalition and join the Spezion Epic Battle. You have a great number of options.