Rainbow mountain
© Getty
Taken in Zhangye National Geopark, Gansu, China, this colourful mountain range spans an area of around 197 square miles. Millions of years of tectonic uplift and compression in sedimentary sandstone and siltstone has led to the formation of a rainbow mountain range. Each layer in the rocky rainbow is packed with different minerals, such as iron and sulphur, which give them striking colours.