Some cemeteries require a burial vault, also called an outer burial container, in order for a casket to be buried in the ground. Before the casket is buried, it's sealed in a concrete or metal structure that helps protect the casket from damage from the weight of the earth above it, water or heavy machinery that may pass over it to reach other nearby burial spaces. The burial vault also protects the beauty of the cemetery by preventing the earth from settling over the burial location. Burial vaults come in several colors and lids can be personalized.