Looking over the car park of the Vesuvius road to Monte Somma. Until 79 A.C., this semicirular ridge on Northern and Northeastern side of the Vesuvius was part of the main mountain. After the big eruption of 79 (when Pompeji was overwhelmed), the magma chamber beneath the mountain was emptied resulting in a huge breakdown of most of the mountain, leaving behind a huge syncline of 4 km diameter, a so called Caldera. (Cauldron). The eruptions since 79 have built up today´s cone of Mount Vesuvius. The grey band in front of the ridge, at the distant end of the valley, is the lava stream from the latest eruption in March1944.
More information on the 1944 eruption (in German)
Video of the 1994 eruption
Video of the 1944 eruption - destructiopn of the town San Sebastian
Another Video - bad quality of the old film material, but from 4´20´´ on you can sea the hot lava stream in front of Monte Somma.
Video from a helicopter flight over Vesuvius