The Mountain of Fire Mount Merapi, Indonesia

Even during its most tranquil periods, Mount Merapi, on the island of Java, smolders. Smoke ominously floats from its mouth, 10,000 feet in the sky. "Fire Mountain," as its name translates to English, has erupted about 60 times in the past five centuries, most recently in 2006. Before that, a 1994 eruption sent forth a lethal cloud of scalding hot gas, which burned 60 people to death. In 1930, more than 1000 people died when Merapi spewed lava over 8 square miles around its base, the high death toll being the result of too many people living too close.

In spite of this volatile history, approximately 200,000 villagers reside within 4 miles of the volcano. But Merapi is just one example of Javans tempting fate in the proximity of active volcanoes—it's estimated that 120 million of the island's residents live at the foot of 22 active volcanoes.