The Frieze was constructed between 420 and 400 BC. Unlike the rest of the temple, the blocks were carved from marble. Each of the 23 stones shows sections of the frieze but it is rare to find any continuation of the design from one stone to the next. It has also been proposed that the stones were not eventually installed as they had originally been proposed in the Temple of Apollo. These two complications are important as when the stones were found they had already fallen to the ground and they were already mixed in with other building rubble. So the stones are arranged in one logical way, but it is not clear if the frieze was actually either intended or designed to be as it now appears.