Interested in getting up close and personal with Naples' past residents? Head underground to visit the Catacombs of San Gennaro. These historic burial places are the oldest in the city and the largest in all of Southern Italy. Spend some time wandering around the different rooms to see how the rooms where the wealthy and poor were buried.
A quick bus ride will bring you to Mount Vesuvius National Park at the foot of the historic volcano. While there are a number of nature walks around the volcano, the real highlight is Monte Somma, the oldest, inactive crater. Hike up to the top with your camera in hand, take a peek at the steam coming out and snap some photos of the Bay of Naples.