Sometimes you actually surprise me: that's a really interesting question. Prior to my visit to Petra, I was in the Timna geological area, in which the Egyptians mined copper. It represents, arguably, the first industrial process, going back almost 3500 years. Somewhere between the Egyptians and the Romans, someone figured out how to create a bellows, and pump air into a fire, making it hot enough to melt the copper in the ore to smelt the metal. On the soil around these ruins you can see many small copper nuggets, the pieces that remained from the copper production. You can see these pieces in green color among the other rock fragments (such as the quartz and granite stone fragments, and the sand grains of the white & red sandstone ). Timna - ancient copper mines Later, tin was added to make bronze. The use of iron may go back to before 1000bc.... This is in Petra....'the theater'....built by the Nabataens...but added to by the Romans. The great Nabataean Theater, still almost completely rock-carved, looks like a typical Roman theater, but it was actually built by the Nabataeans in the first century AD, when the arrival of the Roman Empire in Jordan began to influence the art and the architecture of the indigenous peoples. The Theater is almost entirely dug into the sandstone (the seats are not made of stone blocks, but they are all carved in the mountain) and could accommodate up to about 7000 people. Day tour to Petra, the ancient Nabataean city used as set for Indiana Jones movie. Pictures of Petra.