What term describes underground receptacles for caskets?

The term that describes underground receptacles specifically designed to hold caskets is "vaults." In the context of cemeteries and burial practices, vaults are primarily utilized for protecting the casket from the weight of the earth above as well as from water infiltration. They serve as a strong containment structure that can prevent ground settling and preserve the integrity of the burial site.

Vaults can be made of various materials including concrete, metal, or other durable substances, offering both protection and support. This feature is essential in maintaining the aesthetic and structural stability of the cemetery plot over time.

Other terms provided in the choices represent different concepts within the burial and funeral industry. Crypts are above-ground structures that house caskets, niches are typically wall-mounted receptacles for urns containing cremated remains, and recesses refer to general indentations or cavities that may not specifically pertain to casket containment. Thus, understanding these distinctions is crucial for grasping the terminology used in mortuary and cemetery practices.