august 24 79AD is the traditionally assumed date of the epic eruption of mt vesuvius and the subsequent complete destruction of the cities of pompeii and herculaneum. it's now believed this occurred in october. the thermal energy released by this eruption was a hundred thousands times greater than that released by the bombing of hiroshima.
the last major eruption of vesuvius was in 1944. several villages were destroyed.
the lost and buried city of pompeii was accidentally rediscovered in 1749. today pompeii is a UNESCO world heritage site with 2 million visitors per year viewing it's exposed remains. it has sadly fallen into such a state of neglect that the house of gladiators collapsed in 2010.