The Slytherin Dungeon, also known as Slytherin Common Room is located behind a wall in the cellars of Hogwarts School of Witchcraft and Wizardry. A password spoken to the wall is required to enter it; whereupon a passage is revealed leading down to the common room -- a dungeon-like room with greenish lamps and leather chairs. This dungeon extends partway under the lake, giving the light in the room a green tinge. The common room has lots of low backed black and dark green leather sofas with buttons, skulls as decor, and dark wood cupboards. It has quite a grand atmosphere, but also quite a cold one. The password to the common room changes every fortnight, and it is posted on the noticeboard.