Diodurum Ruins
The Diodurum Ruins are found in northwestern Melunois. This location also has a fast travel point. If you haven’t discovered it yet, it’s just north of Chartres.
Once you reach this area, you’ll see wooden floorboards and a pond.
The path down the floorboards isn’t accessible yet, so we’ll have to swim down the pond to find a passageway.
In the underground chamber, you’ll see some explosive jars and a breakable wall. We’ll need to swim (again) until we reach that room.
Use the jars to destroy the wall. Inside the room, you’ll find the Diodurum key, a Great Shadow Rune, and the Golden Flame Book of Knowledge.
Oh, and if you try to exit using the other direction, you’ll find several beams and poles to help you get past the rats. There’s a wooden fence here and some obstacles that you can move. It’ll lead you back outside at the center of the ruins (the spot with the floorboards).
All right, let’s talk about the Gisacum Ruins in the next part of our Assassin’s Creed Valhalla: The Siege of Paris Hidden Ones Bureau guide.
