A hidden "super volcano" near Pompeii threatens an eruption that could make Vesuvius look like a picnic, scientists warn. The Phlegraean Fields zone of intense seismic activity -- which the ancient Romans believed was the gateway to hell -- could doom millions of people in the Naples area if it erupts, Reuters reports. Scientists plan to drill more than two miles below its surface to monitor any signs of a pending eruption in the huge chamber of molten rock, but some experts fear that the drilling itself could trigger an earthquake or eruption. Areas like the Phlegraean fields "can give...