How to get to every Class 4 Administrative Zone - Tales of Berseria
Class 4 Administrative Zones are essentially Side Quests which you can do periodically throughout the game. In order to unlock a new Class 4 Administrative Zone you'll always have to speak with someone in a town with an " !" over their head. Typically when you arrive in new towns or after major story events there will be a few NPCs with "!" over their heads. Speak with them and sometimes you'll learn about these new zones.
Each Administrative Zone is the same, it's essentially a large arena where you'll do battle against waves of daemon enemies. When you win you'll get a unique reward, typically an armor or weapon that is very powerful for your current spot in the game. On each island you'll find a Katz Chest too, they're all easy to find but if you'd like to see the map locations on each island check out my Katz Chests Locations Guide.
Note: Many of the Class 4 zones that are given to you by a crew member on your ship can be picked up at any harbor. Story Events and Side Quests both are required to unlock many of the available story events.
How to get to Class 4 Administrative Zone - Aberrant Quarter: Speak with a pirate in Reneed after you complete Lothringen Tower.
How to get to Class 4 Administrative Zone - Beast Quarter: Speak with a man on the dock in Yseult's harbor after Haria succumbs to malevolence. This will happen after visiting Palamides Temple during the story of the game. You may also need to complete some side quests first, I believe for me I was able to travel here after defeating the Troll daemon in Haria village which was part of Eleanor's Side Quest.
How to get to Class 4 Administrative Zone - Crustacean Quarter: After claiming Titania as your hideout, speak with a pirate on the docks to unlock the Crustacean Quarter. If you miss it on your first visit to Titania you'll be able to pick it up at a future port from your crew member.
How to get to Class 4 Administrative Zone - Winged Quarter: Once you've completed the story events at Faldies Ruins, return to Titania and speak with one of the pirates on the dock to learn about this Administrative Zone.
How to get to Class 4 Administrative Zone - Apodous Quarter: Complete the Aball Story Quests and then return to Taliesin, speak with a pirate on the docks to unlock this Class 4 Administrative Zone.
How to get to Class 4 Administrative Zone - Demihuman Quarter: This will first be available at Lionel Wharf after you complete the events in Baird Marsh with Teresa and Oscar. However, you will need to do Side Quests prior to being able to accept it. I'm not sure which Side Quests exactly but mine became available after I did the Magilou, Eizen, Eleanor and Laphicet side quests. If you're having trouble making this event appear, travel to each town that you've previously visited and do all of the ! events you can find.
How to get to Class 4 Administrative Zone - Undead Quarter: Speak with members of your own crew at any port town to receive this Class 4 Zone. You'll need to complete the story events at Mount Killaraus as well as maybe some Side Quests (I had to anyway) before you unlock this Administrative Zone. What I did to unlock this is ran around to each town and did all of the ! events, I eventually picked this Class 4 Zone up at Lionel Island Wharf.
How to get to Class 4 Administrative Zone - Fiend Quarter: You can first pick up this Class 4 Zone in Meirchio prior to the events at Mount Killaraus. I was unable to get it at this time though, as apparently there are some Side Quests tied to unlocking it. I picked it up at Lionel Island Wharf after doing the Laphicet, Eizen and Eleanor Side Quests.
How to get to Class 4 Administrative Zone - Armored Quarter: Once you've completed the story events at Mount Killaraus you'll be able to pick up this side quest from one of the pirates in your crew. Some people get it from your crew in Meirchio, however I picked it up by speaking to my crew members at Lionel Island Wharf. I'm pretty sure in order to unlock this Class 4 zone you'll need to complete some Side Quests/events first. I don't know which ones, however.
How to get to Class 4 Administrative Zone - Elite Quarter: To access this Class 4 zone you must first beat the game and then create a save of your completed game after the credits. Once you've done this, speak with the pirate in your crew that has an ! above their head at any port town.