Mount Vesuvius Trail is a 2.4 mile heavily trafficked loop trail located near the city of Ottaviano that features beautiful wild flowers and is good for all skill levels. The trail is primarily used for hiking, walking, nature trips, and birding and is accessible year-round.
Take the bus from Pompeii Train Station.
Take the train to Pompeii when you exit the train, buy a ticket for the bus to the off-road bus to take you to the the trail head. the bus picks up in-front of the train station. bus ride is about 10 minute first bus then another 10 -15min on the off road bus. Hike is pretty easy but has a steady grade. There are good views of the gulf of Naples along the way up and at the top. But you don't have to go all the way up.