There were a number of bathrooms available at Hogwarts, but one of them, known as Moaning Myrtle's bathroom was a particularly gloomy and depressing place. It was home to the schoolgirl ghost of Myrtle Warren - an ex-student who never left the bathroom she was killed in. Myrtle's constant wailing meant that most students avoided the bathroom, but thankfully, Harry, Ron and Hermione's curiosity meant that it led them to one of Hogwarts' darkest secrets.