In this guide, you will find out how to enter The Ruins of Hogwarts Legacy
It is part of a side quest for Poppy, near the end of Poppy’s chain. The door won’t be open for you if you don’t have the quest. There will be a couple of symbols on the door.
There will be two towers around with lights on the top. You have to move the exterior Tower all the way around, and once both towers are aligned, make sure they’re on the circles. After that, the door will open up and you can proceed.