A superb example of badlands, 70 million years ago this arid area with its rugged geology was a lush swamp inhabited by dinosaurs, lizards and fish. Nowadays the soil is dry and eroded, enabling fossils and petrified wood to come to light. Erosion of the different strata has also created the curious-looking formations that stand around many small canyons. Beware, no trails have been drawn or marked out. Do not set off without water.