Platform 9 3/4 - Platform Nine and Three-Quarters

Platform 9 3/4 King's Cross Railway Station, London

Platform 9¾, King's Cross Railway Station, London
Platform Nine and Three Quarters, King's Cross Railway Station, London
Platform 934, King's Cross Railway Station, London

The Platform 9¾ sign is situated in the western departures concourse of London King's Cross railway station, close to platforms 9 and 10, below the walkway leading to the main building.

Platform 9 3/4, King's Cross Railway Station, Euston Road, London, N1 9AL

The ride on the Hogwarts Express starts from King's Cross railway station platform 9¾, which is hidden from view, and reached by walking through the barrier between platforms 9 and 10.

Rowling discovered after the books were published that she had confused the layout of King's Cross with that of Euston station, and that platforms 9 and 10 at King's Cross were not the ones between which she had meant her magical platform to be placed.

There is no platform between lines 9 and 10 at King's Cross. To solve this, the filmmakers re-numbered platforms 4 and 5 for the duration of filming. In reality, at both King's Cross and Euston, platforms 9 and 10 are separated by railway lines. The exterior shots in the film are of the St Pancras Renaissance Hotel, which is part of St Pancras station, adjacent to King's Cross station. From the outside St Pancras is much more visually dramatic than King's Cross.

A plaque depicting the supposed location was placed on the wall in the building containing platforms 9 to 11, along with a luggage trolley 'stuck' halfway through the wall. During the station's extensive renovation works, it was moved temporarily to an exterior wall on the Euston Road, and then in 2012 to the new western departures concourse. A wrought iron 'Platform 9¾' gate used as part of the film set is preserved at the National Railway Museum. Soon after Alan Rickman's death in 2016 fans created a memorial to the actor at platform 9 3/4.

King's Cross is on the historical site of the village named "Battle Bridge", where a road from the ancient city of Londinium crossed the River Fleet, and the Broad Ford Bridge, which according to legend is a battle site between the Romans and the British Iceni tribe led by Boudica, Britain's Warrior Queen, a historical figure in the United Kingdom. Queen Victoria was portrayed as her 'namesake' and restored Boudica as a cultural foundation to Britain. Platform 9 or 10 of King's Cross Station is linked with Boudica's death and possible grave by legend.

J. K. Rowling's parents met on a train at King's Cross Station in 1964. While she was on a train in 1990, J. K. Rowling formed the idea for Harry Potter.