Assassin's Creed Origins: Secret / True Ending guide

In Assassin's Creed: Origins, you’ll get the normal ending after completion of all main quests. For the secret ending, you have to find the twelve stone circles and solve small puzzles. Here, you have to arrange a constellation correctly in the sky. These puzzles you’ll get during the "Bayek's Promise" side quest. Tip: You can turn the constellations to align them with the stars in the night sky.

After completion of the puzzles you can visit the Sphinx in Giza, near the two great pyramids. Go to the north side of the Sphinx, there you’ll find a hidden secret entrance. 

Go inside, there you'll find a large round hall - if you've visited all the stone circles, you'll see twelve bright blue spots on the ceiling. Now, you can interact with the table in the middle of the room - then a secret entrance opens to another hall.

Deep below the Sphinx, you'll find a monolith of First Civilization, the ancient alien race that has left behind in Assassin's Creed over the years repeatedly hidden messages in the Animus. To unlock the message, you'll need fifty silica - these precious stones can be found in AC Origins in the pharaohs' tombs and other dignitaries. 

So before you get the final sequence, you'll have to search all the tombs in the game and collect silica - if you have 50, then you can watch the true ending of Assassin's Creed Origins. Or you can save the search and watch the full-resolution video with the last message from the First Civilization.

Assassin's Creed Origins, Stone Circles Puzzle, Guide, Secret Entrance