The Volcanic Explosivity Index goes up to 8. On that scale, the 1815 eruption of Mount Tambora rates a very destructive 7. The explosion took place on the island of Sumbawa (then in the Dutch East Indies, now in Indonesia) and plunged the region into darkness, but its effects were anything but isolated. Tens of thousands of people were killed by the apocalyptic eruption, subsequent tsunamis and ensuing starvation and disease. The largest volcanic eruption in recorded history changed the world's climate so much (even crops in Europe and North America failed) that 1816 became known as "the year without a summer." Tambora itself shrank several thousand feet and traded its peak for a massive crater at its summit.