The volcano Vesuvius, in southern Italy, erupted in 79 BC, causing death and destruction. The Roman town of Pompeii was located about eight kilometers from Mount Vesuvius. Within a few hours, the city was covered with a thick layer of ash and rock. Some people managed to escape, but around 16,000 people were killed and the city was destroyed. Pompeii was forgotten for over 1900 years. In the 1700s, the ruins of Pompeii were discovered accidentally by archaeologists. They found something amazing. Many of the buildings and houses were preserved under the ashes and they were able to reconstruct the city. It was declared a UNESCO World Heritage Site in 1997.