Crown of Celestine can be found in a secret room in the Sanktleona Castle.
I found the following info on a Chinese website
along the the connection counter wall right away, there is a wall can be worn across the back to front, right, front, left, front, each about 2 seconds to go all players can go treasure room to the rear there is a ninja, he would fall ran chest was 25000GP, 5 Diamonds, Heart ofthe Town come too 703600GP, 63 Diamonds, Crown of Celestine left door to investigate three times to open channel front, straight, walked back to the front barrel has 1036GP, things can be sold
Hope this was helpful