Looking good, is there a way the walls in the room north east from the snake fountain, could look a little thicker, of not it's cool.

As far as furniture, I agree, just enough so you can know which room is which. I found some decent lab table here on the dundjinni forum

the left hand section of the lower right room should be a caged area on big cell basically that opens along the creates a wall. so like a pile of straw in that ares, where prisoners can. maybe with a table for the guards adjacent from the cell door.

The library (the upper most large room) could have a few broken bookcases, and at least one that's still standing. it's going to be an encounter room so some good cover for a bow would be an alright touch.

the armory (room with the thin walls) could have a few weapon racks thrown up against the walls, mostly empty, I have a bow that the party is going to find in there so maybe a table on the southern most wall i'll pop the bow icon on that in D20pro so they can pick it up.

It's looking really good Simon thank you for doing this.