Abstract: A burial vault formed of a polymeric material is disclosed. The burial vault includes a generally rectangular lower box portion and a generally rectangular upper lid portion. Each of the lid and box portions of the vault include substantially parallel lateral ribs integrally formed therein which are in alignment with and cooperate with one another to provide good strength and integrity to the vault. In addition, each of the lid and box portions include weight transferring and weight bearing ledges which assist in the strength of the vault. Fastening and sealing mechanisms are also disclosed which provide good barriers to penetration of air and water into the assembled vault.