In Assassin's Creed Valhalla you can come across Cairns that will give you extra points. On this page of our guide, you will find out where to find Cairn locations in Suthsexe.
You will find the Cairn in the southern part of the region.
It is a very simple task. Arrange the stones so that the entire structure breaks through the blue marking. You don't need to use all stones, four will be enough. To make the task easier, we marked them in the above picture. Remember that you don't need to use them all to rise above the marked height.
This will give you an extra skill point.