Number 12, Grimmauld Place is a fictional location in the Harry Potter series by J.K. Rowling. It serves as the ancestral home of the Black family and is hidden from Muggles by a magical enchantment. The house is located in London and is known for its dark and gloomy atmosphere, filled with family portraits and relics of the past. In the series, Number 12 becomes the headquarters for the Order of the Phoenix, a group fighting against the dark forces led by Lord Voldemort. The house is significant for its role in the story, providing a safe haven for characters like Harry Potter and his friends during their battle against evil.