The Slytherin dormitories and common room are actually located under the lake. Access is gained by going through the door to the left of the main staircase in the Entrance Hall and down the stone steps that lead into a labyrinth of corridors. When given the correct password, a bare stone wall down one of the passages opens into the Slytherin common room. The common room is long and low with a rough stone ceiling and walls. It is lit by green-tinted lamps hanging by chains and carved chairs stand around a fire burning under an elaborate mantelpiece.