The Hogwarts Express departs from London’s Platform 9¾.
In Harry Potter and the Philosopher’s Stone, students reach the hidden platform at King’s Cross railway station by walking directly through the barrier between platforms 9 and 10. The train then carries them to Hogsmeade station before the school year begins.
Platform 9¾ is one of the series’ clearest examples of magical space concealed within an ordinary location. Its number combines the familiar decimal style of railway platforms with a deliberately impossible fraction, making the entrance memorable to readers and viewers.
Readers sometimes confuse the platform with the train’s destination, Hogsmeade, or with the Hogwarts Express itself. The platform is the departure point, while the scarlet steam locomotive is the train. King’s Cross later installed a real visitor photo spot marked “Platform 9¾,” although the fictional barrier is not located exactly between the real stations’ platforms 9 and 10.