This is a sight that you only see if you are arriving at Naples by ship at sunrise. In this shot, you see the sun rising behind the Vesuvius volcano.
Once your ship has arrived, you can also go up there. This is not as adventurous as it sounds though. The first thing they tell you is that the volcano erupts every 64 years on average and the last eruption was... well... 64 years ago. Ooooo... scary! Then they drive you to a point 1000m above sea level and you walk the remaining way (with about 10,000 other tourists).
When we arrived at the top, it was quite hazy, and we could not really enjoy the panorama view. But it was still a memorable day at his famous mountain.