This page details where to find the Guido de Roca Cairn mystery in Amienois, Francia, and how to stack the stones to complete the mystery.
How to Complete the Guido de Roca Cairn
This cairn mystery can be found in the west of Amienois, southwest of Amiens. It’s a fairly simple cairn which requires only the largest and smallest stones to be placed vertically. The other two will need to be placed horizontally between them, as shown in the screenshot below. You’ll need to balance the second largest stone at an angle onto the largest stone.