Archives are a new addition to Assassin's Creed Odyssey: Judgment of Atlantis. They are locations where you can find many items giving you knowledge of Isu. Thanks to them, you will quickly develop your character.
Horus Repository is located in the eastern part of Oikos of Atlantis.
The entrance to the archive is at the bottom of the building. You can notice it easily because the door glows golden.
Enter the location quietly and eliminate the enemies standing in your way. Keep moving down.
An Ainigmata Ostraka puzzle is on the table inside the small room. Be careful - a guard is patrolling the area. Eliminate him and then collect the item.
A hole in the wall is on the right side of the building. Go through it - you will find a chest.
The room located in the deepest part of the location has a codex and a chest with knowledge.