No. 2 - Krakatoa (Krakatau), Indonesia, 1883
When Krakatoa (also spelled Krakatau) blew its top in 1883, it did so with the force of 13,000 atomic bombs. No, really, it's true. They heard the Indonesian island go all the way in Australia, and tsunamis, ashes and toxic fumes overtook entire islands nearby. All in all, over 36,000 people lost their lives and whole villages just went away. The shockwave reverberated around the globe, registering on barographs thousands of miles away. The 1883 eruption destroyed almost the entire island, but, lest there be any doubt that the area is still active, a new island, dubbed Anak Krakatau ("child of Krakatau") has risen in its place ... and it gets bigger every day.