12 Grimmauld Place

12 Grimmauld Place is the address of Black Family home in London which becomes the headquarters for the Order of the Phoenix in Harry Potter and the Order of the Phoenix. It is located in a Muggle neighborhood, but is hidden to people who haven't been told where it is. The house has long been in the Black family, and one of its more colourful previous owners, Sirius's mother, Walburga Black, continues to make her presence felt through the hostile shreiks of her portrait and through the mutterings and insults of her former house-elf, Kreacher. As the house had not been occupied by Sirius during his imprisonment in Azkaban, it required a great deal of cleaning up to make it useable and safe for the Order, and much of this work fell to Molly Weasley.

After Sirius Black is killed at the Department of Mysteries, the house is inherited by Harry Potter. After the death of Dumbledore, Alastor Moody placed a number of enchantments to keep Severus Snape from entering it. These were a Tongue-Tying Curse, a dust-composed form of Dumbledore, which disintegrated when the person it attacks admits that they did not kill it.

The name is another of J.K. Rowling's puns: Grimmauld Place = "grim, old place."