Text Based RPG Game - Working With Multiple ArrayLists

I have come across an issue with arraylists. I am writing a text based RPG game as something to start with ...

Initially I had a single zone which was all stored in an arraylist and everything was working in regards to the player moving around. The problem I now have is how to add further zones to my game. Ideally I would like an arraylist for each zone, and would use the below to create each arraylist

public static ArrayList<RoomsClass> castleMap = new ArrayList<>();

The problem I now have is how to handle the player moving, initially with a single zone/arraylist I could reference that arraylist directly

public void findRoomCoords(int ID) {
for (int i = 0; i < castleMap.size(); i++) {
if (castleMap.get(i).roomID.equals(ID)) {
PLAYER.setCurrentRoomZone(castleMap.get(i).roomZone);
PLAYER.setCurrentRoomX(castleMap.get(i).roomX);
PLAYER.setCurrentRoomY(castleMap.get(i).roomY);
PLAYER.setCurrentRoomZ(castleMap.get(i).roomZ);
}
}
}

My initial thought was to use a getter/setter to remove the reference of castleMap from my movement code in order to access different arraylists, however this is where things have fallen over, I can't seem to work out how to get the arraylist name to change, depending on the outcome of the setZoneMap() method.

public void setZoneMap() {
switch (PLAYER.getCurrentRoomZone()) {
case 0: {
zoneMap = Castle.castleMap;
break;

[Code] ....