How do I finish the room with many useless doors (mausoleum)?

Solution 1:

Enter the marked red doors on the sides that correspond with the treasure maps in the order below:

Treasure map #1Treasure map #2Treasure map #3Treasure map #4

The "C" symbols represent

the numbers one through four.

It isn't necessary to have the maps in your inventory.

Solution 2:

Solution here :

=)