In the Jura Mountains, outside the French village of Plagne, you will find a ~500ft/150m long stretch of dinosaur footprints dating back 150 million years.

After examination, scientists from the Laboratoire de Géologie de Lyon (CNRS / ENS de Lyon / Claude Bernard Lyon 1 University), the Laboratoire Magmas et Volcans (CNRS / Université Clermont Auvergne / Université Jean Monnet / IRD), and the Pterosaur Beach Museum concluded the tracks were left by a Sauropod measuring at least 115ft/35m long and weighing no less than 35 tonnes. Today it is recognized as the longest Sauropod dinosaur trackway ever discovered.

You can read more about this fascinating discovery at the CNRS.