Where is the hidden place in Cron Castle from the book of margahan chapter 4?

Shown here is the location of the hidden place in Cron Castle needed to complete the book of margahan chapter 4.



This location is alittle hard to find at first, but with this screenshot, it will guide you on how to reach the spot. Basically go up the stairs, out the window and walk across a woodway then stonewall. One you get over to the location, you just press R on the light source, similar to the other previous area.