Extracted from Harry Potter: Magical Places from the Films by Jody Revenson
After Rubeus Hagrid hands Harry his ticket for the Hogwarts Express in Harry Potter and the Philosopher’s Stone, Harry is left to get to platform nine and three-quarters by himself. Though he finds platforms nine and ten, he’s baffled at what to do next. Fortunately, the wizarding Weasley family arrives and shows Harry how to go through a brick wall to get onto a hidden platform.
It would be natural to assume that the filmmakers would use King’s Cross station’s real platforms nine and ten for the location shoot. But as Stuart Craig explains, ‘Platforms nine and ten are not in the main station building, but in a little annex to the side.’ Craig wanted to showcase the station’s Victorian architecture and get a strong image: ‘We chose a platform that had big brick piers, under big supporting arches that connected to another platform, which gave it a substantial wall to run at before they pass through it to the other side.’ Platform nine and three-quarters was actually set between platforms four and five.
Throughout the films, going through the wall to the platform was achieved digitally. However, as Philosopher’s Stone director Chris Columbus preferred to use practical effects when possible, he did have a brick-walled passageway constructed in the studio for Daniel Radcliffe (Harry) to run through for the first time. The King’s Cross location was filmed on a Sunday, when the station would be least crowded. And it was uncrowded — that is, until weekend passengers noticed the shoot. Recalls Columbus, ‘We had pulled the real Hogwarts Express onto the platform’s tracks, and had replaced the sign with the one for platform nine and three-quarters. There was a tremendous amount of visitors that day who couldn’t believe they were actually seeing the train at King’s Cross station.’
In Harry Potter and the Deathly Hallows – Part 2, nineteen years after Harry’s graduation from Hogwarts, he, Ginny, Ron, and Hermione return to platform nine and three-quarters: now, as parents accompanying their children, who are taking the train as Hogwarts students. Once again the platform held not only the train but, nearby, delighted onlookers.