There are a slew of new Hogwarts secrets that you can discover in the Challenges section of your menu. These include Legendary Chests, collection chests, and appearance rewards. One particular Hogwarts secret is the mysterious metal door across from the Headmaster's Office. It's here that you will locate a key.
In Hogwarts Legacy, how do I open the door opposite the Headmaster's Office?
You'll need to get the metal key door to access the Headmaster's Office. Take the Trophy Room Floo, walk through the room, and to the right where there is a gated staircase. Continue ascending the stairs until you reach the entrance to the Headmaster's Office. The locked metal door will be to the right at the end of the hall.
To unlock the door, you'll need a special key locked away in a room within the Headmaster's Office. This means you'll need to have Niamh's Trial completed in order to gain access to the office. You'll also need a level three Alohomora, which you can obtain by finding Demiguise Moons.
Find the locked door beside a telescope on the left side of the room, which will be a level two lock. This leads outside to another staircase leading up to a level-three lock door. This is possible only if you have all Alohomora upgrades.
Once you unlock the metal door, you'll notice a desk of sorts, and at the very edge of the fireplace, a key that you can interact with. Pressing X or Square will unlock the door.
Exit the Headmaster's Office and go down the spiral staircase to the entrance hallway. Once inside, you'll be able to open the door with the key. At the bottom of the stairs, you'll also find a field guide and two collector's chests.
Keep an eye out for more secrets and puzzles in Hogwarts Castle and grounds. There are many to solve, and all have a worthwhile reward.
Do you want more Pro Game Guides Hogwarts Legacy content? Check out our guides on All Daedalian Key locations in Hogwarts Legacy or What to Do at the Map Wall in the South Wing in Hogwarts Legacy!