The Hogwarts train departs from Platform 9¾ in J.K. Rowling’s Harry Potter books.
The hidden platform is located at London’s King’s Cross station and can be reached by passing through the barrier between platforms 9 and 10. Harry first learns about it after meeting the Weasley family, who show him how to enter the magical platform. The Hogwarts Express then carries students to Hogsmeade station near Hogwarts.
In the real King’s Cross station, platforms 9 and 10 are separated by railway tracks, so the films used a different location for the barrier scenes. A Platform 9¾ shop and luggage trolley display became popular visitor attractions at the station. The fraction is written as three-quarters, not as a decimal, and it is part of the platform’s distinctive fictional name.