Deep within the castle of Hogwarts, one may just come across a stone wall that doesn't look all that different from the other many walls in the castle. However, to Slytherin students, they know exactly what to do. With the right password given to the wall, it slowly crumbles away to reveal the entrance. Housed beneath the lake of Hogwarts, this house is light in green tones and can be slightly drafted. The windows, with views of the underwater world of the surrounding lake, can be quite entertaining.