Those are called gabions and are typically made of welded wire. They are used to inexpensively reinforce the ground for civil projects. They are common in the U.S.
Also in France.
Now, I used to study geology and I can GUARANTEE they serve a much more important purpose... I can't tell much, but let me just point out that no one has been attacked by rocks in areas where this has been implemented.
Now, I used to study geology and I can GUARANTEE they serve a much more important purpose... I can't tell much, but let me just point out that no one has been attacked by rocks in areas where this has been implemented.