Gabions are modular building bloks formed of welded wire mesh and filled on site with rock, stone or crushed concrete. They are filled on the premises, often with locally available material and are an effective and relatively inexpensive capital cost.
Gabions can be placed as sloping "mattresses" or as near vertical cubic baskets. Steel-welded gabion baskets are very robust wire mesh rock-filled baskets primarily used as retaining walls.