Have your tree Yule Ball ready or show your love for Harry Potter with Nemesis Nows range of Harry Potter hanging decorations. Here we have the Platform Nine and Three-Quarters sign, immortalised in resin and ready to hang in your home. Platform Nine and Three-Quarters (Platform 9) was a platform at King's Cross Station in London. Magically concealed behind the barrier between Muggle Platforms Nine and Ten, this Platform was where Hogwarts School of Witchcraft and Wizardry students boarded the Hogwarts Express every 1 September, in order to attend school.