Platform Nine and Three-Quarters is a secret platform located at the Muggle King's Cross Station in London. It serves as the departure and arrival point for the Hogwarts Express, the train that transports students to and from Hogwarts at the beginning and end of each term. To access the platform, a witch or wizard must walk or run directly at the seemingly solid barrier that divides the Muggle platforms nine and ten. The barrier functions as a magical gateway, allowing magical folk to pass through unharmed while remaining solid to any Muggles who might accidentally run into it. The platform itself is described as bustling and crowded, filled with students and their families saying their farewells. A scarlet steam engine, the Hogwarts Express, is always found waiting at the platform before its departure at precisely eleven o'clock on September 1st. A sign on the train or platform typically reads “Hogwarts Express, Eleven o'clock.” The platform's origins are not detailed in the novels. However, according to supplementary materials, the platform was established in the 19th century by Minister for Magic Ottaline Gambol as a discreet method for transporting hundreds of students to Hogwarts. The decision to use a prominent Muggle station was controversial, but it was implemented through the use of complex Memory Charms and what was described as the largest mass Concealment Charm ever performed in Britain (Pottermore).
Platform Nine and Three-Quarters is a significant recurring location that symbolizes the gateway between Harry Potter's mundane life in the Muggle world and the excitement of the wizarding world. It is the site of many important meetings, farewells, and transitions throughout the series.
As a specific, self-contained location, Platform Nine and Three-Quarters does not have numerous distinct sub-areas, but its key components include: