"I think the Slytherin common room has a spooky beauty."
-- J.K. Rowling (TLC)
The Slytherin common room is a long, low-ceilinged, dungeon-like room filled with skulls and the like. There are high-backed chairs and a carved mantlepiece on the fireplace. The walls are rough stone. The light is green from the green hanging lamps and because it’s located under the lake (CS12,DH23).
- The principle description of the Slytherin common room comes from CS12 when Harry and Ron visit the common room disguised as Crabbe and Goyle: "The Slytherin common room was a long, low underground room with rough stone walls and ceiling from which round, greenish lamps were hanging on chains. A fire was crackling under an elaborately carved mantelpiece ahead of them, and several Slytherins were silhouetted around it in high-backed chairs." (CS12)
- Harry and Ron visited the Slytherin Common Room disguised as Crabbe and Goyle through the use of Polyjuice Potion (CS12)