A hidden storage space can refer to a variety of different places, such as a CACHE, LOFT, ATTIC, CLOSET, or SILO. A CACHE is a collection of items stored away in a hidden or hard-to-reach place. A LOFT is an upper room or story in a building, usually in the ATTIC. An ATTIC is a space directly below the roof of a house, often used for storage. A CLOSET is a small room or enclosed space used for storage, typically built into the wall of a house or other building. Finally, a SILO is a tall cylindrical structure, typically made of concrete or metal, used for storing grain or other materials.