There are many puzzles for you to solve in Assassin’s Creed Valhalla, one of them being the standing stones puzzles. These kinds of puzzles require you to find a specific spot to stand and use your Odin’s Vision to line a series of images up to form a bigger picture.
You can find one of these puzzles in Vinland, an area of the game you can unlock after you progress the story a good amount and finish the Lunden arc. Here, you can find the Tionontate:ken standing stone puzzle.
In the center of the stones will be one with a symbol carved into it that you can interact with. Doing so will trigger Brendan of Clofert to speak, and after this, you can use your Odin’s Sight to reveal all the different images on the stones surrounding you.
Before you find the right spot to stand at, you will need to move two stones out of the way. These are among the stones and you will need to them to the left to get out of your way.
Now for finding the right spot: climb up onto the tallest rock in the middle and look down. The camera should automatically zoom in slightly, and all you have to do is move it around until your controller starts to vibrate. Eventually, there will be a shimmer, meaning you have solved the puzzle.
You’ll get a Skill Point from it, and a section finished for the Mysteries in Vinland.