The Dungeon Corridor is a long, gloomy stone corridor that leads from the narrow spiral staircase, coming down from the Viaduct Entrance, to the staircase leading down to the blank stone wall which is the entrance to the Slytherin Dungeon. The Potions Classroom, and possibly Severus Snape's office, can be found along this corridor. The Slytherin Corridors are probably adjacent to this corridor.