Abstract: An underground reinforced plastic enclosure comprising a vertically and circumferentially stiffened body. The body is made of a fiberglass polyester resin and the stiffeners are of a reinforced plastic mortar. The body is suitable for surrounding a transformer or an oil switch used in underground utilities. On the body is seated a top cap made of reinforced plastic mortar. The top cap is formed with a central opening. Seated on the top cap is a reinforced plastic mortar cover plate or a metal grate. Depending from the top cap is a fiberglass polyester resin baffle and tamper shield. The body seats on a base of reinforced plastic mortar. A grade adjustment skirt also depends from the top cap outwardly from the baffle and tamper shield.