Once at the summit of Mt. Vesuvius, a trail leads around more than half of the rim, allowing peeks into the caldera that formed when the volcano blew its top in 79 AD, burying the Italian cities of Pompeii and Herculaneum, among others. If you look closely, you can spot steam rising from a vent within the collapsed cinder cone, as this volcano is still considered to be active and dangerous.
