Mythburg is the large, developed, multi-species inhabited, port city that gets a lot of shipping traffic from the Tropeical Sea, famed for having an academy of magic. It is in the Havenspass region and is currently the most dominate hub for trade in the area due to location and size.
Mythburg is divided into districts. Each district has literal walls around it which keep things moderated, by City Watch, between districts. To travel between districts a person must be well known or have proper documentation or reason. This method has proven effective to keep the populace from acting up.
Since Mythburg only exists as part of the Player Backstories that brought it to life, it is really just around to fill out a Player (not DM) conceived section of the campaign setting. Therefor what the Players need it to be, to make of it, matters. To which I cannot reiterate enough, this is not part of the Dungeon Master's master plan. It is instead some wonderful bonus content that influences the overall.