A Geological/Topographical Reconnaissance of Hannibal's Invasion Route into Italia in 218 BC.

During the Second Punic War, in 218 BC, the route Hannibal followed from the Rhône River to the Alps is subject to some controversy. A reconnaissance undertaken in summer 2002 assessed the most likely invasion route as across the Col de Grîmone to the area around Gap in the Durance River Basin, thence east along the Guil River that would take the Carthaginians to the Col de la Traversette, the main alpine pass north of Mt. Viso. Once into the upper Guil Valley, Hannibal encountered snow and firnpack, both formidable physical and psychological barriers. However, on the lee side, a rockfall blocked his passage below the 2800 m contour. Employing the ingenious strategy of ordering trees felled, timber laced around boulders and set alight, it took three days to clear a passage through the rockfall so that his starving army could wind its way along the Po River to the fertile plains below. [ABSTRACT FROM AUTHOR]