Location from harry-potter-chamber-of-secrets by
A dark side street off Diagon Alley where Harry ends up after a Floo powder mishap, stumbling into Borgin and Burkes just as the Malfoys are selling dark artifacts ahead of Ministry raids.
Harry arrives here by accident -- his first time using Floo powder sends him spinning past his intended destination and dumps him in Borgin and Burkes, where he hides in a vanishing cabinet just as Lucius and Draco Malfoy enter. He watches Lucius sell dark artifacts from his home to avoid Arthur Weasley's raids, buying a cursed necklace and sneering about blood traitors. Hagrid finds Harry wandering the dark alley and steers him back to Diagon Alley. The detour is Harry's introduction to the seedier side of the wizarding world -- the place where dark magic is bought, sold, and treated as ordinary commerce.
A cramped, dingy alley perpetually shadowed. Shop windows display shrunken heads, cursed necklaces, and jars of unsettling substances. Borgin and Burkes has a dusty window full of skulls and dark artifacts.
Also known as: Knockturn Alley, Borgin and Burkes