Once you have completed all your required assignments in Wizard City, Merle Ambrose will ask you to investigate Krokotopia.
Once you have been given that quest, you can access the Spiral door by entering Bartleby the World Tree.
After you’ve completed Krokotopia, you can move on to Marleybone, then MooShu, then Dragonspyre. You can visit Grizzleheim at level 5, but cannot return until level 20.
I have a quest to go to Krokotopia, but I cannot get in. How do I complete a quest when I do not have access? :(
This happens sometimes, especially if you get a quest from your school's professor. Just continue to follow the storyline and finish whatever area (Wizard City?) that you are working on. Eventually you will gain access to Krokotopia and be able to do your quest. It's annoying, but it will probably happen again.
This also happens to me for crafting quests. They'll try to send you to the next craft instructor, but having that quest doesn't unlock the next world.
