C116 is Mrs Chapman's classroom. It is ridiculously long and therefore people on either end of the classroom cannot actually see the board. Students avoid talking in here our of fear that their conversations may be echoed across the room.
This is also the room where a ceiling tile fell from the roof and therefore covered the back corner of the classroom in bits of smashed ceiling for a few days, despite the destruction Mrs Chapman had a very calm reaction and didn't pay it much attention.
On the walls of C116 you can find photos from a Year 9 Camp from probably a few decades ago, some mathsy related posters, and some paper shapes on the windows.*
(*The fashionable interior design mentioned above hasn't been changed since at least 2015)