In Harry Potter and the Philosopher’s Stone, the wizarding pub Harry visits in London is the Leaky Cauldron.
Hagrid takes Harry there after collecting him from the Dursleys and explains that the apparently ordinary London location is a gateway to Diagon Alley. The pub’s entrance is concealed behind a wall in the courtyard, which can be opened using magic.
The Leaky Cauldron is an important meeting place in the wider Harry Potter story. In the film, it provides Harry’s first extended introduction to the wizarding world and leads directly to his shopping trip for school supplies. It is also frequently confused with the Three Broomsticks, a pub in Hogsmeade that Harry visits in later films, or the Hog’s Head, another Hogsmeade inn.