12 Grimmauld Place is the ancestral home of the House of Black. It is located in London, in a Muggle neighbourhood, and the location is protected by a Fidelius Charm. Because the house is invisible to the neighbourhood residents, the Muggles have long since accepted the odd numbering system that landed number 13 Grimmauld Place next to number 11.
In 1995, the home became the headquarters for the Order of the Phoenix, with consent of Sirius Black.
