After you entere the Enterance Hall, you take a walk down the staircase that leads down to the duengon's. You enter the Duengon's Corridor's, it's a dark hall with a statue of a gargoyle, and several other door's that leads to Potions, Slughorn's Office, his Storerom, a corridor that has the enterance to the Slytherin Common Room, and the Dueling Corridor.
