Parque Nacional Talampaya and Parque Provincial Ischigualasto

Between them, the parks of Talampaya and Ischigualasto cover just under 700,000 acres and contain the most the world's most complete fossil record of the Triassic period (245-208 million years ago), giving palaeontologists a clear picture of the evolution of dinosaurs, plants, and mammals. The importance of the parks and the finds in them went unnoticed until the 1950s; both parks were made UNESCO World Heritage Sites in 2000.

To help preserve the parks, entry is limited to 1,350 visitors a day so arrive early in peak periods of January, February, July, and Easter Week. Ischigualasto (also known as Valley of the Moon, though the Quechua name prevents confusion with its namesake in Chile) is 80 km (50 mi) from Talampaya in the province of San Juan and generally considered to be the more impressive of the two. That said Talampaya's vast walls of rock, whittled by wind and rain into strange formations, may be unlike anything you've ever seen. Besides strange rocks and fossils, both parks bear witness to human presence, with petroglyphs from thousands of years ago.