Hogwarts Express passengers use Platform 9¾ in J.K. Rowling’s Harry Potter books.
The hidden platform is located at London’s King’s Cross Station and is reached by passing through the barrier between platforms 9 and 10. Harry first learns about it when the Weasley family helps him find the train before his first journey to Hogwarts.
Platform 9¾ is a fictional location, but King’s Cross Station is real. The books use the station as a boundary between ordinary Muggle London and the wizarding world. The Hogwarts Express departs from the platform on 1 September each year.
The fraction is written with the three-quarter symbol in the name. Because the fictional platform is so strongly associated with the real station, King’s Cross later installed a commemorative luggage trolley that appears to pass through a wall, making the setting a popular visitor attraction.