The Hufflepuff Dormitories and Common room are accessed through a painting near the kitchens. It is a quite cozy and welcoming place; not at all like a dungeon. The room is filled with yellow hangings and fat armchairs, with little underground tunnels that lead up to the dormitories, which have round barrel-top like doors

Gryffindor Tower is located behind the portrait of the Fat Lady on the Seventh Floor of Hogwarts School of Witchcraft and Wizardry. A password is required to enter it, spoken to the portrait. A circular hole is behind the painting, leading to the common room, which is a circular room where Gryffindor students can relax after a long day of studying. The common room is full of squashy armchairs, tables, and a bulletin board where school notices, ads, lost posters, etc. can be posted. A window looks out onto the grounds of the school, and a large fireplace dominates one wall.

The Slytherin Dungeon is located behind a wall in the cellars of Hogwarts School of Witchcraft and Wizardry. A password spoken to the wall is required to enter it; whereupon a passage is revealed leading to the common room -- a low-ceilinged, dungeon-like room with greenish lamps and chairs. This dungeon extends partway under the lake (which is why it has green-coloured lamps).