Abstract: A curved concrete forming structure to provide a 1000 psf system for forming curved walls having a radium in excess of 5'. The structure includes a series of arcuately curved metallic panels secured in stacked side-by-side assembly. The improvement particularly concerns a panel which is comprised of a flexible metallic skin plate. Spaced vertically extending ribs are positioned along the length of the panel on one side thereof. The ribs and the skin plate have essentially the same vertical dimensions. A pair of vertically spaced arcuately curved angles are provided which angles have identical diameters that correspond to the diameter of the concrete wall to be poured using the concrete forming structure. The curved angles are substantially stiffer and inflexible compared to the flexible skin plate.