Places
Borgin and Burkes
A shop in Knockturn Alley dealing in Dark objects. Harry arrives there accidentally by Floo powder and overhears Lucius Malfoy offering objects for sale. Tom Riddle works there after leaving Hogwarts.
In the books
Harry Potter and the Chamber of SecretsChapter: 4
Harry’s Floo journey goes wrong and he emerges inside the shop instead of Diagon Alley.