All the staff mentioned prior that the Naples port is known for pick pocketing and to be careful with belongings. We got off the boat around 7:30AM and walked to the train station which was about a 20-25 mins walk. Since it was early in the morning, there were not a lot of people around in the city. We took the train to Ercolano in order to see Mt. Vesuvius. The one way train was 1.80 euros, but the train attendant ripped us off by not giving us the correct amount of change. We sat at the front of the train and the train attendant assisted to ensure that we got off the train. Note: we were surprised with the amount of graffitti on the exterior of the trains. Outside of the Ecrolano train station, there is a travel/tour store which we booked a bus and entrance to Mount Vesuvius (16.50 euros/pp) which is the only live volcano on the mainland of Europe. The bus is the only way up to the mountain. We were on the bus for 10 with 3 other couples. It's a 15-20 minute drive up vertical and narrow roads. Upon reaching the parking lot, the bus provides you 1.5hrs to climb the mountain and walk around. Make sure to be wearing running shoes or hiking shoes, as the path consists of dirt and loose rocks. It was fun hike to the crater and beautiful views of the cities below and sea. After Mount Vesuvius we were dropped back off at the same train station, and we walked down the street (towards the water) to Herculaneum which is a smaller archelogical site. You can walk above it and see the overview of it for free (prior to the entrance). We decided to take the train to Pompeii (for 1.40 euros/pp) to see the city ruined by the volcano eruption of Mount Vesuvius. Pompeii is much larger than we thought and we only had 2.5 hours and didn't even cover off half the map. We took the train to Sorrento (approx 1.80 euros/pp), which appeared to be a very nice city. We didn't get to stay long since we wanted to catch the last Hydrofoil (11 euros/pp) back to Naples. The ride was 45 minutes and quite rocky through the waves. But on the upside, it docked right next to the port and was a 5 minute walk back to the cruise ship.