Castle basement locked?

[mouseshly]

Hi! I ended up building the castle before any of the other houses since I didn't realize there was a progression system. Since then I have built the other 2 and both of their basements are open and functional but the castle's still isn't.

I have all the books and completed the story and all of the dungeons. I also watered all the flowers and wasn't sure what triggered the teleporters. We have also already accomplished the top of the Jungle. I have also tried rebuilding the castle by demolition and have reloaded the game but nothing is working.

Is it a bug or is there something within my power?
Thank you in advance!

[blinglog]

its underneath the stairs the very obvious castle basement door is fake and confused me at first too. you have to move the camera to see the real basement door