Abstract: A water and weather resistent coffin is made of a layer of hardened plastified fiber mat and a second layer made of hardened end-grain balsa core panel. The side walls of the coffin are connected to the bottom wall by a pair of squares along each side wall. The squares are formed of narrow plates connected to each other by a triangeloid linking plate. The cover and the box of the coffin have a corresponding perimeter separated by a sealing strip. The cover is hingedly mounted on the box and is adapted to be locked to squeeze the sealing strip. The great resistence of the material used and its structure allows the lateral walls of the box of the coffin to remain straight when a cadaver lies on the bottom wall. The walls of the coffin are flat to maintain a light weight and their original shape under normal stress.