This mystery can be found in the centre of Hamtunscire at Heald Tor, just north of the city of Wincestre, AC Valhalla.
Stack the Stones to Complete the Cairn
This is one of the more difficult cairn mysteries in the game. To reach the required height threshold with the stones, you don’t actually need to use all of them. You will need to stack the larger stones vertically rather than horizontally, though, as shown in the screenshot below. Try to follow the structure we have created below. It should be relatively stable so long as you position the stones correctly. Don’t worry if they fall off as you try to stack the stones, this will be a process of trial and error as you balance them.
Once you’ve stacked the stones in a stable way to the required height threshold, validate the positioning to complete the mystery.