Explore Patagonia The RN-3 coastal route Parque Nacional Los Glaciares The RN-40 and the Cordillera Share The BOSQUE PETRIFICADO SARMIENTO is home to perfectly preserved 65-million-year-old tree trunks, randomly strewn across a near-lunar setting with a stunning purple-and-orange cliff backdrop. Formed by mineral-rich water permeating the wood over hundreds of thousands of years, effectively turning the trees into stone, the petrified forest has parallels with the Monumento Natural Bosques Petrificados, but its bands of “painted desert” soils are more striking and erosion processes are much more visible here. Traversing the 2km circuit is rather like walking around a sawmill, the ground covered by splinters of bark and rotten wood that chink under foot, except that these woodchips are Mesozoic. The highlight is a famous and much photographed chunk of hollow fossilized log that looks like nature’s take on a giant drainage pipe. Take water, sunscreen and hats as the sun can be very strong, as can the winds. There are toilets in the park, but no other services.