You have regions as levels with areas as sublevels. The levels or regions are named Gwania, Burroughs, and Furoma. Sublevels for Gwania are Meadows and Town for Novice; Harbour for Apprentice; Mountains for Journeyman. Sublevels for Burroughs are Laboratory, Mousoleum, Town of Digby, Bazaar.
Sublevels for Furoma Region is Training Grounds, Dojo, Meditation Room, and Pinnacle Chamber.
When you reach Master, you can then go to the next level up which is Burroughs, Laboratory. BUT ONLY after you have obtained The Burroughs Laboratory Map Piece. You must catch a Ninja Mouse from the Mountain in order to obtain The Burroughs Laboratory Map Piece. Take note that not all Ninja Mouse has the Map. Therefore try to obtain the Map before you move to the rank of Master.
reaching the rank of Master, the player is eligible to hunt in the
Laboratory, Town of Digby, and Mousoleum locations of the Burroughs
area, assuming they have collected the proper loot. It is also the
first ranking at which Radioactive Blue Cheese Curd Potions can be
collected and used. The Master also acquires another increase in
crafting abilities. The rank of Master is signified by a purple shield
next to the player's name.
From what I gather The Burroughs area is far away from town where the
shops is and there are certain items you need to stock up on like Super/Brie+, Swiss and Marble. You need a certain trap and base when you go to the upper
levels for better chances of hunting. You will at least need a Swiss Army Mouse Trap with Stone Base or other better traps which may be more expensive for you at this point of time.
In the Laboratory, you need to find the Key to the Town of Digby by successfully catching a Dwarf Mouse in the Laboratory. Not every Dwarf Mouse in the Laboratory carries a Key. After obtaining the Key, you may visit the Town of Digby.
while in the laboratory the only way you can also move to the Mousoleum by getting the Tattered Mousoleum Map Piece. The Tattered
Mousoleum Map can only be obtained by successfully catching a Zombie
Mouse in the Laboratory. You also need to collect as many Radioactive Blue Cheese Curd Potion in the laboratory as you can. You will need it to create Radioactive Blue Cheese for use in the Mousoleum. 1 Radioactive Blue Cheese Curd Potion can convert 10 Brie to 10 Radioactive Blue Cheese and cost you 300 Gold per piece. The best is to use the Radioactive Blue Cheese Curd Potion to convert 10 Super Brie to 10 Radioactive Blue Cheese and cost no Gold. The best is to have 300 Radioactive Blue Cheese for hunting in Mousoleum.