Gabions or Gabion Mattresses are rectangular containers (baskets) fabricated of thick galvanized wire, which are filled with stone and stacked on one another, usually in tiers that step back with the slope rather than vertically. The most common civil engineering use of gabions is to stabilize shorelines or slopes against erosion. Other uses include retaining walls, temporary floodwalls, let down structures, small or temporary/permanent dams, and channel lining.

Gabion baskets have some advantages over loose riprap because of their modularity and ability to be stacked in various shapes; they are also resistant to being washed away by moving water. Gabions also have advantages over more rigid structures because they can conform to ground movement, dissipate energy from flowing water, and drain freely. Their strength and effectiveness may increase with time in some cases, as silt and vegetation fill the interstitial voids and reinforce the structure. They are sometimes used to keep stones which may fall from a cutting or cliff from endangering traffic on a thoroughfare.

There are variations in gabion design, there are various special designs of gabions to meet particular functional requirements and some special terms for particular forms have come into use.

Mattress: a form of gabion with relatively small height relative to the lateral dimensions; commonly very wide. For protecting surfaces from wave erosion, channel lining, slope protection. Mattresses are typically 6 inch, 9 inch, and 18inches in thickness.

Baskets: a form of gabion which is much thicker usually 18 inches to 3 foot in thickness.

Lengths and widths of gabion baskets and mattresses are typically divisible by three. Typical widths and lengths are 3, 6, 9, and 12 foot in any combination.