The invention is related to a method of manufacturing a wall panel and a wall panel system. The method includes: forming a glass-fiber reinforced rigid magnesium oxide layer including the steps of: pouring or injecting a slurry of uncured magnesium oxide into a mold, embedding glass fiber reinforcing material therein, and curing the magnesium oxide to obtain the glass-fiber reinforced rigid magnesium oxide layer having a first side and a second side; applying, to the second side of the rigid magnesium oxide layer, an insulation layer, the insulation layer comprising a foam; and applying to the first side of the rigid layer a veneer layer.