Hogwarts School of Witchcraft and Wizardry is a school of magic somewhere in Europe. The Headmasters during the time of Harry Potter were Albus Dumbledore, Minerva McGonagall and Severus Snape. There were certain staircases at Hogwarts that changed where they led to every Friday, as well as some with vanishing steps. There were doors that would open only when asked politely or tickled, and solid walls pretending to be doors.