The word in this context means something like ideas, comments, notes. When you think of something that you find interesting or just want to say your thoughts about the castle, you can write it down and send it to them.
Anyway, my cousin works there, if you found something else wrong in the translation, I can tell her and I'm sure she can pass the info on to somebody responsible
![Cheesy :D](http://forum.adrenalinex.co.uk/Smileys/default/cheesy.gif)