Abstract: A burial vault (1) designed to hold a standard casket (10), having a dome-like cover unit (2) and a generally rectangular base unit (3), each unit being of the same size so as to mate together around the edges (19,20) at a joint section. The cover unit has a plurality of interconnecting reinforcing ribs (15) running lengthwise along side walls (13) and end walls (11), across a top wall (14) and vertically down the side and end walls of the cover unit. The vertical ribs (16, 12) on the end of the side walls are sufficiently open and wide enough on a bottom end to fit over and interlock with ribs (6) on side walls (21) of the base unit. The joint section around the edges of the units consists of concave flange (9) in the cover unit which is received by a concave flange (5) in the base unit when the units are mated to form a burial vault.