Ki and Gil will enter this room through either the door at the top-left of it (if they came from Dining Room), or the one at the bottom-left of it (if they'd came from Colosseum). It contains eight Green Slimes, two Green Oozes and four "Green" Ropers (which are orange and take fifty-two hits to kill).
This is the first room in the game where the tops of the walls are coloured peach-orange instead of emerald-green or ochre-yellow (see the image).
The key at the top-left of the room opens up the aforementioned door at the bottom-left of the room, the key at the top-right of the room opens up the aforementioned door at the top-left of the room, the key at the bottom-left of the room opens the door at the bottom-right of the room - and the key at the bottom-right of the room does not open any of the doors in the room. Therefore, there's no key for the remaining door at the top-right of the room.
The aforementioned door at the bottom-left of the room leads back to Colosseum (Room Pass: HC2), the aforementioned door at the top-left of the room leads back to Dining Room (Room Pass: 732), and the door at the bottom-right of the room leads off to Knight's Chamber (Room Pass: HC9).
