In a huge expanse between the Upper Provence Alps and the Var, the Geological Reserve of Upper Provence, signposted out of Sisteron, is dotted with hiking paths and viewpoints. Spread over several sites, it chronicles 300 million years of the Earth's history. Highlights include the Isnards' ammonite slab at Digne and the ichthyosaurus site of La Robine, the Land and Earth museum at Sisteron and the Road of Time.