Method of forming a wall panel

A prefabricated wall panel has a precast body including at least one decorative design element. In addition, the wall panel includes a mounting element having a first end embedded in the precast body and a second end projecting from the precast body. A groove is formed between the precast body and the second end of the mounting element along a first edge of the precast body. A tongue is formed along a second edge of the precast body opposite the first edge. The tongue and groove cooperate to allow prefabricated wall panels to be more easily installed on a support substrate.