in Mordred's castle
under the library in the castle
In front of Hades castle.
keep going right if it doesn't work you'll see arrows to the castle
You get the chese for a mouse in the left room in the destroyed castle in astro knights in poptropica
get the moldy cheese and get the mouse in the castle
Nothing
To get to the queens castle in poptropica you go to early poptropica then you go to poptropica towers.after that keep walking left until you see a purple building and it says rooftop resturuant you go all the way to the top and you will see a vine.Climb the vine an then just keep going right
if you mean in astro knights, the mcm is in the library in the castle
The arrow is at the castle
You get the cordniteres on Astroknights island from the castle from the King and Queen.
It's an underwater cave at Poseidon's "castle"