The Slytherin Dungeon 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 to the Common room -- a low-ceilinged, dungeon-like room with greenish lamps and chairs. This dungeon extends partway under the lake (which is why it has green-coloured lamps). The common room has lots of low backed black and dark green leather sofas with buttons, skulls, and dark wood cupboards. It has quite a grand atmosphere, but also quite a spooky, cold one.
