In northwestern China’s Gansu province, at the northernmost extent of the Tibetan Plateau, the landscape offers layer upon layer of spectacularly colorful rocks. The first image shows Zhangye National Geological Park, which spans 322 square kilometers (124 square miles) of the prefecture of Zhangye. Colorful rocks are not confined within the park boundaries. The second image shows an area about 150 kilometers (100 miles) northwest of the geological park. Like the park’s rusty rocks, these sandstones are from the Cretaceous and appear strikingly red.