Cupboard Under the Stairs

The Cupboard under the stairs was Harry's home for a long time, until he was allowed to move into Dudley's second bedroom when he started Hogwarts, it was then used by the Dursley's to store all magical objects of Harry's when he was staying at their house.

It was discrbed as small and dusty, with lots of spiders. When Harry got sent his first Hogwarts letter, it was addresses: The Cupboard under the stairs.