The Gryffindor common room is located in one of the castle 's highest towers , the entrance to which is on the seventh floor in the east wing of the castle and is guarded by a painting of The Fat Lady , who is garbed in a pink dress .
The Gryffindor Common Room ( the place where the Gryffindor students spend their time and do their homework ) is in one of the castle 's towers , at the seventh floor .