Dudley: "They stuff people's heads down the toilet the first day at Stonewall. Want to come upstairs and practice?"
Harry: "No, thanks. The poor toilet's never had anything as horrible as your head down it -- it might be sick."
— Harry responds coolly to Dudley's teasing.[src]

Stonewall High is a state secondary school in the United Kingdom that the Dursley Family had planned for Harry Potter to attend. The school's uniform was grey, but in an effort to save money, Harry's Aunt Petunia dyed some of Dudley's old clothes to make a grey uniform for him, which according to Harry, smelled like elephant skin.

According to Harry's cousin, Dudley Dursley, new students at Stonewall High are subjected to a hazing ritual in which their heads are stuffed down a toilet on their first day. It is possible that they bully younger and weaker children, like Harry.

It was not to be, however. For, later that day, Harry received a letter of admission to Hogwarts School of Witchcraft and Wizardry. Despite the Dursley's best efforts to keep Harry from reading let alone accepting said invitation, even going as far as hiding in the Hut on the Rock, such efforts proved futile thanks to the intervention of Rubius Hagrid. Thus, Harry was spared a bleak fate at Stonewall High.