Vesuvius, Italy: A.D. 79
The eruption of Mount Vesuvius buried not just the Roman city of Pompeii, preserving many of its murals and houses, but also Pompeii's neighbor on the Bay of Naples, a city called Herculaneum. The death toll for the blast was estimated to be more than 10,000.
The Roman historian Pliny the Younger recorded the only eyewitness account of Vesuvius's wrath. But remains of the two cities were finally discovered in 18th-century excavations.