Not the London Zoo?
220.127.116.11 just raised a very good point. In Harry Potter and the Philosopher's Stone, chapter 5, page 67, it states "Harry had never been to London before." This is when Hagrid has taken Harry from the Dursleys to get his school supplies in Diagon Alley, which is some time after the zoo trip. It seems likely then, that in the book at least, it was a different zoo. - Nick O'Demus 12:56, September 10, 2009 (UTC)