Destroying the ancient cities of Pompeii and Herculaneum, the infamous volcano Vesuvius still poses a threat to nearby Italian cities. When this unpredictable volcano erupted in 79 AD, thousands of people were killed and many were left in the ash that took over the area. We know so much about this eruption thanks to an eyewitness named Pliny the Younger. He wrote letters after the eruption in which he recounted the type of eruption and the destruction it caused, all from his view of the two-day catastrophe many miles away (Ball, 2014). Currently, this large volcano sits at 4,203 feet (Wikipedia, 2014 ), but this was not always the case. The composite, otherwise known as a stratovolcano, was constantly enriched by lava overflowing from the cone, while rock and other pyroclastic debris were also ejected. Initially formed by the subduction of the African plate beneath the Eurasian plate, water from the oceanic African plate lowered the melting point of the mantle, creating the magma that led to the volcano (Wikipedia, 2014). Then, seventeen thousand years ago, following an explosion, a caldera was formed and the cone of Vesuvius was formed inside it (Wikipedia, 2014). In 62 AD an earthquake occurred which is thought to be the beginning of the volcanic activity that caused the explosion of 79. It caused a lot of damage around the Gulf of Naples, and especially in Pompeii (Wikipedia, 2014). Researchers believe that tectonic activity caused new activity in the volcano, with tremors becoming more frequent within days of the eruption (Wikipedia, 2014). On the morning the most destructive eruption occurred, Pliny described it as “a stone pine, since it rose to a great height on a kind of trunk and then divided into branches…. Sometimes... halfway down the paper... ten kilometers below the surface (Wikipedia, 2014). It is monitored by the multiple stations of the Vesuvius Observatory, which use numerous techniques to track the level of the magma. They measure ground movements and for this purpose analyze the gases emitted by the volcano (Wikipedia, 2014). Since Vesuvius does not pose a danger in the near future, it has been declared a national park. There is a network of trails around the mountain leading to the summit, open to visitors (Wikipedia, 2014). Works CitedBall, Jessica. “Mount Vesuvius – Italy”. Mount Vesuvius, Italy: maps, images of the eruption, Pompeii. Geology.com, 2014. Web. May 7, 2014."Mount Vesuvius." Wikipedia. Wikimedia Foundation, May 6, 2014. Web. May 11, 2014. Owens, James. "Ancient Roman life preserved in Pompeii." Mysteries of the ancient world. National Geographic, August 16, 2010. Web. May 7 2014.