“Where did you come out?” Ron asked.
“Knockturn Alley,” said Hagrid grimly.
“Excellent!” said Fred and George together.
“We’ve never been allowed in,” said Ron enviously.
“I should ruddy well think not,” growled Hagrid.

Harry Potter and the Chamber of Secrets - Chapter 4 : At Flourish and Blotts
See this quote in the Pensive -