This girls' lavatory (also known as Moaning Myrtle's bathroom) is situated on the first floor of Hogwarts Castle. It has been out of order ever since a student named Myrtle was killed there. Myrtle has haunted the bathroom ever since, leading it to be a place most students do not want to enter. This bathroom holds the entrance to the Chamber of Secrets. To get in the Chamber, a person needs to say "open" in Parseltongue. This will cause the tap with a snake on the side (a tap which incidentally, never worked) to move into the floor, revealing a tunnel which leads downwards into the Chamber. The Girls Lavatory is located in a corridor that connects the Viaduct Entrance and the Stone Bridge to the Transfiguration Courtyard. But feel free to come in if you dare to face Moaning Myrtle