Places
The Leaky Cauldron
The Leaky Cauldron is the dingy pub that stands between Muggle London and Diagon Alley. Witches and wizards pass through it on the way to the alley. Harry stays there before his third year, after he leaves the Dursleys, and the Minister for Magic meets him in a private parlor.
First mention
Harry Potter and the Philosopher's StoneChapter: Diagon Alley
Hagrid leads Harry into the pub from Charing Cross Road, and Tom the barman greets the boy who lived.