Located down the left passage leading from the Hufflepuff common room, the boys' dorms are seperated by year.

Located down the right passage leading from the Hufflepuff common room, the girls' dorms are seperated by year.

Located directly underneath the Great Hall, this room is just the same size. Preparation tables are located directly under their counterparts in the hall above, and the food is magically transported through the ceilings and on to the waiting plates above. Staffed by over one hundred house-elves, food is readily available at any given time, provided you know how to access the area. A painting of a bowl of fruit in the corridor leading to the Hufflepuff common room is where the door is located, and to get it to appear, one need only tickle the pear and the knob will pop up.

This classroom is always cold, especially in winter. Pickled animals in jars line the walls, and other notable fixtures besides the work tables are the student cupboard, gargoyle sink, and the blackboard on which course instructions are usually written out for reference.

Located almost directly below the lake, the Slytherin common room is perhaps the most bleak of the four houses. Long with low ceilings, the room is very much like a dungeon and the level on which is located. Green and silver decorations are everywhere, and even the light coming from the fixtures fixed to the low ceiling seems to come out green.

Located down the left-hand passage leading from the Slytherin common room, the boys' dorms are seperated by year.