The Caretaker's office is officially Room 234-00, and it can be found in the circular building adjacent to the Entrance Hall, on the Ground Floor of Hogwarts Castle. It's a small, simple room with a single oil lamp hanging from the ceiling. It smells a very little bit of charcoal. There are filing cabinets in it, with details of the misdeeds of Hogwarts students since time immemorial. One of those cabinets is full of confiscated magic items marked "Confiscated and Highly Dangerous.". Behind a curtain, there's a bed and a chair. There is also a desk and an armchair. This office is currently unoccupied.