Foothills of the French Alps at sunset. In the Late Cretaceous Period (between 100 and 66 million years ago) the African plate collided with the Eurasian plate resulting in the folded mountain chains of the Alps. Around the main mountain chains are ranges of foothills although many of the peaks exceed 610 meters (the definition of a mountain). The range of foothills in the far south west, the Provence Prealps, includes Mont Ventoux (left), 1909 meters high and often included in the Tour de France. Photographed in the evening after a storm on the Drome/Vaucluse border, France.