Just go in the castle and look for the first door on your right.
in the castle
The dungeon is in the castle library.
if you mean in astro knights, the mcm is in the library in the castle
The library is in the Castle, to the right on the first floor. The three areas of the kingdom are the Village, the Castle, and the Mill.
Mordred had often been going to the same location in the castle library (castle, first floor right).
In the library on the bottom floor there is a green brick on the wall click on it .it will lead you to the dungen.
in the castle library click mcm in the non-fiction section to get into the dungeon
find it yourself thanks click on some books in the castle library in the nonfiction place
Go to the library and then there will be a sign that says McM. Click on it and you're in!
This is the first item on the island. Go to the Mordred Musseum and spend it. Get the library slip and go to the castle library.
you have to keep going right. it is past the village. the library, the princesses room, and the king and queen should be in there.
There is a hidden stairway to the dungeon in the castle library, and a hidden opening under the fountain.