Travelling through the map in Assassin's Creed Odyssey: Judgment of Atlantis, you will encounter the mission called Lighten Up. It is available on the world map and will be added after having a conversation with a man. After completing this mission, you'll get another one.
This mission begins with a conversation with Neokles. He will give you a new task. It's a logical puzzle.
First, you have to push a stone block that reflects light. All you have to do is walk up to it and push it to the ground.
Then jump down and adjust the block so that it does not reach the rays.
After that, break down the vases that are blocking the passage of the rays. By doing so, you will complete the first part of the puzzle.
Your next task is to set the another blocks so that the light may reflect from them. After installing everything go to Neokles. He will give you another mission.