Sword of the Sea has 23 Stele collectibles that are required to be interacted with for the trophy / achievement Wisdom of the Ancients.
Stele are stone pillars that can be found in each level that when activated provide background lore about the game. When you collect a stele within a level the yellow text on the pillar will disappear to show it has been interacted with, but this is unfortunately reset in NG+ and Chapter Select so on replays of levels you can’t tell which you have already collected unless you remember yourself.
Stele Locations
Veiled Sea
Stele #1: The Sea Remembers – In the first area after the title, follow the wall to the left to find a group of lanterns. Ride through them to turn them on to reveal a cave. Interact with the stele with 
.
Stele #2: The Necropolis – In the second area of the level after interacting with the water point on top of the pillar to the left, bounce up to the higher ledge using the new jellyfish to find the stele.
Stele #3: The Blade – Keep to the left wall where you can find a group of lanterns on a slope. Turn them on to reveal an entrance, then go inside and activate the second set of lanterns to lower the sand inside the cave. Follow the path into the cave on the left to reach a water point, then you can interact with a stele to the right of the large mural.
Stele #4: The Fish Swim in the Sky – After activating the water point on top of the building that activates the left chain, look to the right (facing the entrance of the building) and you can see one of the sets of windows is open with a platform behind it. Inside this room is the stele.
Stele #5: The Cycle is Broken – Follow the other chain to the right side of the area, and on the left before the door you can find the stele on a platform.
Stele #6: Auma – After activating the water point that activates the right chain, go behind the building where you can travel up some kelp after returning the water to the area. Follow the path at the top of the waterfall to a platform with the stele at the end.
Lost Grotto
Stele #7: Not All Wars Have Victors – In the area with the water ball near the door, activate the lanterns on the right to drop the sand and reveal the stele.
Stele #8: The Great Dolphin – Follow the path past the door and the stele is on the platform with the crystals and shark statues.
Stele #9: The Lost Grotto – After activating the first sphere water point, use the kelp to reach the rooftops of the area, then the stele is in the middle of the building in the middle of the rooftop area.
Stele #10: The Champion – After activating the 4 switches to open the door, this is in the same room as the turtle mouth to its right.
Shadow Tundra
Stele #11: Fire Elemental – After the scene dropping through the ice, the stele is directly in your path.
Stele #12: Ghost Warrior – At the third statue (you can’t go far off the correct path in this tundra area, keep moving in the direction the statues are looking) it is on the ground in the hand of the buried statue.
Stele #13: The Ghost Warriors Undoing – When you reach the open area with the giant statue in the middle, go down the path to the right to a mural with the stele in front.
Stele #14: Forgotten Eras – In the next area you have the ability to use boosts by picking up wisps from the lit pillars. Go to the top of the area and use the boosts to reach the doorway on the left (facing down the hill). At the back of the same cave on the lowest level, under some stone snake heads you can find the stele.
Stele #15: The Dual of the Sea – In the large open area after activating the first golden bell, go to the left side of the central pit near the tall platform with the three pillars. There is a cave behind it where you can find the stele.
Stele #16: The Great Shark – On the left side of the area on the platform with the bell, go around the back where the stele is sitting in the chest hole of a shark statue.
Sacred River
Stele #17: The Minder’s Wisdom – After the intro about water rails, the stele is located in the large room before going up the ramp.
Stele #18: The Tower – After entering the large outdoor area, this is down on the left near the boats stuck on pillars.
Stele #19: The Sacred River – After raising the giant boat, jump into the back where there is an opening to find the stele in one of the rooms.
Stele #20: The Value of Legend – After activating the water point on the floating island to activate the final part of the bridge to the level exit, use jellyfish from the middle level of the central building to bounce up to one of the smaller islands where you can find the stele at the top.
Boiling Cavern
Stele #21: The Fires Below – After opening the door with the water bubble, the stele is on the right side of the room just behind the rock.
Stele #22: The Army of Red Fire – In the large room with all the boats, stick to the right side where you can find a stele around the corner.
Stele #23: When Water Battles Fire – When you reach the room with the skeletons you can grind, the stele is on the second level at the end of the second one.
