London inspired J.K. Rowling’s idea for the Hogwarts Express departure point at King’s Cross station.
In the Harry Potter books, students travel to Hogwarts by boarding the train at the fictional Platform 9¾ at London’s King’s Cross station. The station is a real major railway terminus serving routes to northern England and Scotland. Rowling has said that King’s Cross was important to her family because her parents met on a train traveling from King’s Cross to Scotland.
The magical platform is placed between Platforms 9 and 10 in the story, although the real station’s platform arrangement does not perfectly match the fictional description. A Platform 9¾ sign and trolley installation became a popular visitor attraction at the station.
The answer is London rather than Edinburgh, even though Edinburgh is strongly associated with Rowling’s later writing life. She wrote parts of the series in Edinburgh, but the Hogwarts train’s departure point is specifically tied to King’s Cross in London.